Intestinal Protein Digestibility Research Articles

The Use of The Ancient Amaranth (Amaranthus) Grain in Traditional Turkish Cuisine

With its culinary use dating back more than six thousand years, amaranth is known as the ancient grain and the food of the future. Recently recommended for consumption by FAO/WHO, the amaranth plant is a prominent, “forgotten,” functional food that can be used in human nutrition because of its drought-resistant cultivation, gluten-free, and protein and fiber-enriched content. This study evaluates amaranth's botanical character, functional properties, impacts on health, preparation-cooking methods, and use in local and traditional Turkish cuisines. Numerous studies have indicated the association between amaranth’s chemical composition and its anti-oxidative, anti-tumor, gluten-intolerance, and cholesterol-lowering properties, and its assistance with intestinal flora and protein digestibility. Manifold dishes can be made using amaranth seeds and flour in traditional cuisines. Raw and cooked amaranth grains are used in rice, soup, and breakfast cereal. In the food industry, it is a crucial grain alternative to various bakery products, such as bread, pasta, cookies, manti, noodles, biscuits, and crackers, made from amaranth flour. There is a need for alternative recipes to increase the use of amaranth in the kitchen. In this context, it is thought that awareness should be increased by applying it to recipes that can replace semolina and bulgur in traditional cuisines. For this purpose, this study aims to increase the consumption of the ancient grain amaranth by including it in recipes in traditional Turkish cuisine.

Effect of encapsulated Medinilla javanensis fruit extract on growth, protein digestibility and health of broilers

The study investigated the effect of encapsulated Medinilla javanensis fruit extract on performance, protein digestibility, and health of broilers. A total of 200 Cobb broiler chicks were divided into five treatments with four repetitions, including T0 (basal diet), T1 (basal diet + 200 mg/kg encapsulated Medinilla javanensis fruit extract), T2 (basal diet + 400 mg/kg encapsulated Medinilla javanensis fruit extract), T3 (basal diet + 600 mg/kg encapsulated Medinilla javanensis fruit extract), and T4 (basal diet + 800 mg/kg encapsulated Medinilla javanensis fruit extract). Sample collection was conducted on day 35 of age. Results showed that increased encapsulated Medinilla javanensis fruit extract levels in feed linearly increased (P<0.05) body weight, body weight gain, intestinal lactic acid bacteria counts, protein digestibility and serum superoxide dismutase levels, while linearly decreasing (P<0.05) feed conversion ratio, intestinal Escherichia coli counts, small intestinal pH values and serum malondialdehyde levels. In conclusion, encapsulated Medinilla javanensis fruit extract improved growth performance, protein digestibility intestinal health and antioxidant status of broilers. The encapsulated Medinilla javanensis fruit extract at a level of 600 mg/kg exerted the best performance and health of broilers.

Ruminal degradation and intestinal digestion of developed oat (Avena sativa L.) varieties in comparison with barley grain in dairy cows

This study aimed to evaluate the ruminal degradation and intestinal digestion of nutrients of two cultivars of oat grains (CDC Nasser and CDC Seabiscuit) in comparison with a barley grain (CDC Meredith that was considered the control treatment) in dairy cows. Nasser showed higher rumen undegradable protein (RUP; P < 0.01) and intestinal digestible protein ( P < 0.01) than Seabiscuit or control. However, the total digestible protein was not different among grain varieties ( P = 0.25). The in vitro intestinal digestibility of RUP (dIBP) for Nasser was higher than control ( P = 0.02); however, the dIBP in Seabiscuit did not differ from other cultivars. The intestinal digestible rumen bypass starch and total digestible starch were lower in the oat grain varieties than in the control ( P < 0.01). The truly absorbed protein supplied to the small intestine (DVE) was highest for control, intermediate for Seabiscuit, and lowest for Nasser ( P < 0.01). Moreover, control showed a higher estimated feed milk value than oat varieties ( P < 0.01). In conclusion, Seabiscuit shared similar rumen degradation and intestinal digestibility with control suggesting that Seabiscuit oat grain could in some extension replace barley grain in diets for dairy cows.

487 Rumen degradation, N-To-Energy Synchronization, and Intestinal digestion Study in dairy cows: Effect of oat varieties and types (feed type vs. milling type)

Abstract This study aimed to determine the impact of four oat varieties and types (feed type vs. milling type) on the rumen degradation kinetics of nutrients, intestinal digestion of nutrients, and N to energy synchronization. Twelve samples [4 varieties (Arborg, Haymaker, Nasser, Summit) × 3 harvested years (2018, 2019, 2020)] were used for in situ rumen incubation analysis, three-step in vitro analysis, and available N to energy synchronization evaluations. The experiment design was RCBD design (oat varieties as a fixed effect and harvested year as a random block effect). Statistical analysis was performed by MIXED procedure model of SAS 9.4, and significance was declared at P < 0.05 and tendency at 0.05 ≤ P < 0.10. Results showed that Haymaker and Arborg oat had higher rate of degradation of degradable fractions (Kd) of dry matter (DM), crude protein (CP), and starch than that of Nasser oat (P < 0.05). Nasser oat had greatest rumen bypass dry matter (BDM, g/kg DM), and rumen bypass feed starch (BST, g/kg DM) in these four varieties (P < 0.05) while the effective degradability of dry matter (EDDM, g/kg DM), effective degradability of feed crude protein (EDCP, g/kg DM), and effective degradability of feed starch (EDST, g/kg DM) of Nasser oat were least among varieties (P < 0.05). There were significant differences in BDM, EDDM, %BST, and EDST between milling oat and feed oat. For the intestinal nutrient digestibility, Summit oat had greatest intestinal digestibility of rumen bypass dry matter (%dBDM) among four varieties (P < 0.05), and the value of intestinal digestible rumen bypass dry matter (IDBDM, g/kg DM) of Summit was greatest in these varieties, which has greater IDBDM (g/kg DM) content than that of Nasser oat (P < 0.05). Nasser oat also had the least total digestible dry matter (TDDM, g/kg DM) in these varieties (P < 0.05). Summit oat had similar intestinal digestibility of rumen bypass protein (%dBCP) with Haymaker and Nasser oat but had greater %dBCP content than that of Arborg oat (P < 0.05). Nasser oat had greater intestinal digestible rumen bypass protein (%IDBCP, % of CP) in these four varieties (P < 0.05), while its value of total digestible protein (TDCP, g/kg DM) was the smallest and the TDCP content of Nasser oat was less than Haymaker oat (P < 0.05). Summit and Arborg oat had greater total digestible feed starch (TDST) than that of Nasser oat (P < 0.05). Significant differences were found on %dBDM, IDBDM, TDDM, and TDST between the feed type and milling type oat (P < 0.05). Haymaker oat had similar ratio of N to organic matter (OM) of the oat (N/OM) with Nasser oat but had greater N/OM content than that of Arborg and Summit oat (P < 0.05).

Decreased Amino Acid Transporter LAT2 Is the Main Determinant of Impaired Protein Utilization During Aging

As the global demographic shifts toward an aging population, understanding the efficiency of protein utilization in older adults becomes crucial. Our study explores the intricate relationship between protein intake and aging, with a focus on precision nutrition for older people. Through a meta-analysis, we confirm a decline in protein-utilization capacity in older individuals and examine the different contributions of plant and animal protein. In experiments involving mice of different ages, older mice exhibited decreases in the biological utilization of four proteins (casein, beef protein, soy protein, and gluten), particularly casein. In subsequent research, casein was studied as a key protein. A decline in gastric digestion function was observed through peptidomics and the examination of pepsin levels using casein. Nevertheless, this decline did not significantly affect the overall protein digestion during the aging process. The combined application of targeted amino acid metabolomics identified abnormal absorption of amino acids as the underlying cause of decreased protein utilization during aging, particularly emphasizing a reduction in branched-chain amino acids (BCAAs) in older mice. Delving deeper into the proteomics of the intestinal protein digestion and absorption pathway, a reduction of over 60% in large neutral amino acid transporter 2 (LAT2) protein expression was observed in both older humans and aged mice. The reduction in LAT2 protein was found to be a key factor influencing the diminished BCAA availability. Overall, our study establishes the significance of amino acid absorption through LAT2 in protein utilization during aging and offers a new theoretical foundation for improving protein utilization in the older adults.

Nutritional Evaluation of Milk Thistle Meal as a Protein Feedstuff for Diets of Dairy Cattle.

The objective of this work is to investigate the chemical and nutritional value of milk thistle meal (MTM) in order to improve it and to provide theoretical support for its application in dairy cattle production. MTM was assessed in comparison with seven conventional protein feed sources, namely, soybean meal (SBM), cottonseed meal (CS), canola meal (CN), palm kernel meal (PK), rice bran meal (RB), corn germ meal (CG), and sesame meal (SS). The chemical composition of these feedstuffs was assessed using wet chemical analysis, the Cornell Net Carbohydrate and Protein System was used to evaluate the carbohydrate and protein fractions, and the in situ nylon bag technique and the modified three-step in vitro method were used to assess the rumen degradation and intestinal digestibility. Additionally, Fourier transform infrared technology was used to determine the feedstuff protein spectral molecular structure and its amino acid profile was also assessed. The result showed that MTM acid detergent fiber, lignin, unavailable nitrogen, and non-degradable carbohydrate content were higher than those of the other feedstuffs. It had a 17% and 36% rumen effective degradation rate of neutral detergent fiber and dry matter, respectively, and had the lowest small intestinal rumen undegradable protein digestibility rate. It was low in leucine, histidine, arginine, and proline, but high in methionine. The total area of amide I and amide II in the protein secondary structure was similar to that of CN and CS, and the amide I and II ratio was not different from that of RB. To sum up, MTM has a poor carbohydrate composition and is high in fiber but, in comparison to most other protein feeds, has a higher crude protein rumen effective degradation rate, similar to that of SBM, and it is a good source of methionine, a limiting amino acid. Hence, its nutritional value can be further improved for application in dairy feeding through processes such as microbial or enzymatic fermentation.

Characterization of ruminal degradation, intestinal digestion and total true nutrient supply to dairy cows from feedstocks and coproducts from Canola bio-oil processing: Impact by source origin.

The objective of this study was to characterize ruminal degradation, intestinal digestion and total true nutrient supply to dairy cows from canola feedstock (canola seeds) and coproducts (meal and pellets) from bio-oil processing which were impacted by source origin. The feedstocks and coproducts (mash, pellet) were randomly collected from five different bio-oil processing plants with five different batches of samples in each bio-processing plant in Canada (CA) and China (CH). In situ rumen degradation kinetics were determined using four fistulated Holstein cows with incubation times at 0, 2, 4, 8, 12, 24 and 48 h. Intestinal digestions were determined using the three-step in vitro method with preincubation at 12 h. The DVE/OEB and National Research Council systems were applied to evaluate the truly absorbable nutrient supply to dairy cows and feed milk values (FMVs). The results showed that in situ undegradable fractions (U) (p = 0.025) were higher in CA meals, and potentially degradable fraction of D was higher (p = 0.016) in CH meals. CH meals had higher total digestible dry matter (TDDM, p = 0.018) and intestinal digestibility of protein (dIDP, p = 0.016). Canola meals from CA had lower MREE (microbial protein synthesized in the rumen based on available rumen degradable protein; p = 0.011) and DVME (rumen synthesized microbial protein digested in the small intestine; p = 0.011) and had higher ECP (endogenous protein in the small intestine, p = 0.001) and absorbed endogenous crude protein (truly absorbed ECP in the small intestine) than CH (p = 0.001). The FMV evaluated based on the metabolic protein and net energy showed no differences between CA and CH in both coproducts and feedstocks.

Evaluation of Vicia faba plant genotypes using non-destructive vibrational molecular spectroscopic technique (ATR-FT/IR): molecular structure profiles of protein in relation to nutritional characteristics

This study aimed to evaluate the impact of genotypes and tannin levels on the nutritional characteristics of faba bean seeds and their relation to protein molecular structure profiles using Fourier transform infrared spectroscopy (FTIR). Eight genotypes with low tannin (LT, n = 3) and normal tannin (NT, n = 5) levels were studied. Standard methods of analysis and NRC 2001 were used to obtain chemical and energy parameters. The protein molecular spectral study was performed using a spectrometer JASCO FT/IR–4200. Molecular features were analyzed in the mid-infrared region at ~4000–800 cm−1 and protein-related functional groups were obtained using OMNIC software. Results showed higher ( P < 0.01) soluble crude protein (SCP), rapidly degradable protein fraction (PA2), and intestinal digestibility of bypass protein (dIDP) in LT than NT. The slowly degradable protein fraction (PB2) was higher in NT ( P < 0.01) compared to LT. Higher absorbance was observed in spectral peaks related to amide I, amide II, and β-sheet in NT ( P < 0.05) compared to LT. The area ratio of amide I to amide II and the height ratio of α-helix to β-sheet were higher in LT compared to NT ( P < 0.01). This study provides a better understanding of associations between structure and nutritional characteristics in faba bean genotypes with different tannin levels.

Discovery of a novel series of medium-sized cyclic enteropeptidase inhibitors

Enteropeptidase is located in the duodenum that involved in intestinal protein digestion. We have reported enteropeptidase inhibitors with low systemic exposure. The aim of this study was to discover novel enteropeptidase inhibitors showing more potent in vivo efficacy while retaining low systemic exposure. Inhibitory mechanism-based drug design led us to cyclize ester 2 to medium-sized lactones, showing potent enteropeptidase inhibitory activity and improving the ester stability, thus increasing fecal protein output in vivo. Optimization on the linker between two benzene rings resulted in discovery of ether lactone 6b, exhibiting further enhanced enteropeptidase inhibitory activity and long duration of inhibitory state. Oral administration of 6b in mice significantly elevated fecal protein output compared with the lead 2. In addition, 6b showed low systemic exposure along with low intestinal absorption. Furthermore, we identified the 10-membered lactonization method for scale-up synthesis of 6b, which does not require high-dilution conditions.

In situ ruminal degradability and intestinal digestibility of dry matter and crude protein of low-protein fraction from sunflower meal

The objective of this study was to evaluate rumen degradation kinetics and intestinal digestibility of low-protein fraction from sunflower meal (LPSFM). Three non-lactating Jersey cows with an average body weight of 436 ± 18 kg fitted with a rumen and T-type duodenal cannulas were used in the experiment. Five samples of LPSFM from different batches produced in 20-d intervals were collected and incubated in the rumen of the cows for 0, 2, 4, 8, 16, 24 and 48 h in 6 replicates. The average CP content of LPSFM was 175 (SD = 6.98) g/kg. Data were fitted to nonlinear regression model and analyzed statistically using SPSS. The soluble or rapidly degradable fraction а of LPSFM dry matter (DM) ranged from 105 to 137 (SD = 11.3) g/kg. The effective degradability of DM at assumed rumen outflow rate of 0.06/h ranged from 293 to 338 (SD= 16.3) g/kg. Fraction a of CP ranged from 124 to 189 (SD = 23.9) g/kg. Effective degradability of LPSFM CP at rumen outflow rate of 0.06/h ranged from 515 to 560 g/kg (SD = 16.2). Intestinal digestibility of LPSFM (after 16-h rumen incubation) DM and CP measured by the mobile bag technique varied from 318 to 349 g/kg (SD = 10.5) and from 766 to 820 g/kg (SD = 17.7), respectively. The average estimated Protein Digestible in the small Intestine (PDI) and Rumen Protein Balance (RPB) of the LPSFM samples analyzed in the current study, following equations in the Bulgarian feed evaluation system (at 0.06/h outflow rate), were 113 (SD = 1.67) g/kg and 125 (SD = 14.9) g/kg, respectively. The protein degradability and digestibility values obtained in this experiment can be effectively used in formulating rations for ruminant animals.

Impact of processing methods (dry-heating, autoclaving, and (microwave irradiation) on protein-related molecular structure spectral feature and protein nutritive value of cool-seasoned oat varieties in ruminant system in western Canada

The objectives of this study were to reveal the effects of heating method and variety on (1) protein molecular structure spectral features revealed by Attenuated Total Reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and (2) ruminant relevant protein chemical profiles, protein subfractions, rumen degradable protein (RDP), rumen undegradable protein (RUP), and intestinal protein digestibility using the Cornell Net Carbohydrate and Protein System (CNCPS) in oat varieties [CDC Nasser (feed-type oat) and CDC Seabiscuit (milling-type oat)]. Heating method included control (raw), dry heating (DH), moist heating (autoclaving, MH), and microwave irradiation (MIR). The dry matter (DM), crude protein (CP), and neutral detergent fiber (NDF) contents in CDC Nasser were 934, 107, and 252 g/kg DM, respectively; the contents of these nutrients in CDC Seabiscuit were 933, 110, and 268 g/kg DM, respectively. Heat processing significantly affected the total RDP (TRDP, P < 0.001), which was higher for DH than MIR and MH in CDC Nasser (5.46%, 5.01%, and 4.45%DM). Conversely, MIR had a higher value for TRDP than DH and MH in CDC Seabiscuit (5.32%, 5.24%, and 4.51%DM). The total RUP (TRUP) was higher for MH than MIR and DH in both varieties (P < 0.001). The intestinal digestible feed protein was similar between the varieties (P = 0.308); however, DH and MH reduced the value, while MIR increased it compared to the control (P = 0.010) for both varieties. The results from the ATR-FTIR analysis showed an interaction between varieties and heat processing in the protein secondary structures α-helix (P = 0.003), β-sheet (P = 0.031), and their ratio (P = 0.030). Moreover, in the multivariate analyses, no independent groups were observed between the raw and the three heat processing methods in the protein-related molecular structure of oats. In conclusion, heat processing altered the protein subfractions, the TRDP, and TRUP, affecting intestinal protein digestibility. The ATR-FTIR spectroscopy with univariate molecular analysis showed heat processing-induced molecular structure changes in the protein-related spectral profiles in CDC Nasser and CDC Seabiscuit.

Effect of processing with ozone on in vitro and in situ ruminal degradability and intestinal digestibility of feather meal protein

This study aimed to investigate the effect of processing feather meal (FM) with ozone (O3) gas on nutrient content, ruminal degradability, and intestinal digestion of crude protein (CP) using in vitro and in situ techniques. Experimental treatments were designed as control (not-processed), O3-processed FM for 12 h (h; treat 1), O3-processed FM for 24 h (treat 2), and O3-processed FM for 48 h (treat 3). Five Ghezel sheep equipped with ruminal cannulas were used to measure the nutrient degradability and to obtain ruminal fluid for in vitro gas production. Processing with O3 gas significantly decreased dry matter (DM), ether extract (EE), and Ash content of the FM compared to the control (P < 0.05). Processing FM by O3 increased the volume of in vitro gas production (P < 0.05). The soluble and potentially degradable fractions of the DM and CP showed a significant increase with increasing processing time (P < 0.05). Processing with O3 gas increased quickly degradable protein (QDP), rumen degradable protein (RDP), effective rumen degradable protein (ERDP), and digestible undegradable protein (DUP) content as a proportion of feather meal CP. Still, undegradable dietary protein (UDP) decreased significantly. Intestinal digestibility of rumen undegradable protein (RUP) and Metabolize Protein (MP) content of the FM was also significantly increased with increased processing time and the highest values were achieved after 48 h of processing (P˂0.05). According to the results of this experiment, it can be concluded that processing FM using O3 for 48 h increases its nutritional value in ruminant nutrition.

Effect of thermal processing methods on structural, physicochemical and nutritional characteristics of cool-season chickpeas in ruminant systems

The focus of this study was to evaluate the effect of thermal processing methods: Dry Heat, Wet Heat (Autoclave) and Microwave Irradiation on newly developed cool-season adapted CDC chickpeas as an alternative source for protein and energy for ruminant. Three varieties of chickpeas, developed and provided by the Crop Development Center (CDC), were CDC Alma, CDC Cory, and CDC Frontier. All varieties were grown in three different locations in Saskatchewan: Elorse, Limerick, and Lucky Lake. For dry heat related processing, the samples were placed in the oven at 100 °C for 60 min. For wet heat related processing (Autoclave), the samples were placed in the autoclave at 120 °C for 60 min. For microwave irradiation, the samples were microwaved for 3 min (900 W). The results showed that soluble crude protein (SCP) and non-fiber carbohydrate (NFC) were highly decreased by autoclave treatment. Moderately degradable protein fraction (PB1) was greater in autoclave treatment. There was no significant difference in indigestible protein fractions (PC) among all heat processing methods. Autoclave treatment was lower in rapidly degradable carbohydrate fractions (CA4) but greater in slowly degradable carbohydrate fraction (CB3). As to energy value parameters, there were different in total digestible nutrients (TDN) value among processing treatments with greater value in dry heat and microwave treatments. However, there was no difference in net energy for lactation (NEL3X) among processing treatments. In rumen degradation kinetics, there were no differences in DM rumen degradation kinetics among processing treatments. However, the heat processing affected in situ potential degradable fraction (D) and undegraded fraction (U) of protein. Autoclaving treatment had greater in situ potential degradable fraction but lower undegraded fraction. The processing did not significantly affect rumen bypass protein (BCP) or rumen undegradable protein (RUP) and effective degradation protein (EDCP). For protein intestinal digestion, heat treatments did not affect intestinal digestibility of rumen bypass protein (%dIDP) and intestinal digested crude protein (IDP). For DM intestinal digestion, heat treatments affected digestibility of rumen bypass DM (%dBDM) with greater values in dry heat (90.3%) and microwave (86.5%) and lower value in autoclaving (67.7%). However, total (IDBDM) and intestinal digested dry matter (TDDM) were not significantly affected by processing treatments. For hourly effective degradable ratios (ED_N to ED_DM), microwave showed a greater value. Total true protein supply (DVE value) was not significantly different among processing treatments with average of DVE value of 100 g/kg DM. All three processing methods (dry heating, wet heating, microwave irradiation) had positive degraded protein balance (OEB value) with average of 62 g/kg DM, indicating potential shortage of energy in rumen. Feed Milk Value based DVE value showed no difference among processing treatments. When applied NRC dairy, the results showed that the processing methods also did not significantly affect total Metabolizable Protein supply (MP) to dairy cows with average MP of 82 g/kg DM. But based on NRC model, all treatments had negative degraded protein balance (DPB value) which is different from DVE/OEB system. In conclusion, the response and sensitivity to thermal processing methods of CDC chickpeas showed difference. But important nutrient supply to dairy cows in terms of NEL3x, DVE, MP, OEB, and FMV were not significantly different among processing treatments.

Evaluation of a dacitic (rhyolitic) tuff breccia use on performance, inflammatory, and antioxidant responses in broilers mildly challenged with Eimeria spp.

The objective of the study was to investigate the effects of a dacitic tuff breccia (DTB) on Eimeria-infected broilers. A total of 600 one-day-old Cobb 500 male chickens were randomly assigned to 5 treatments with 10 replicates of 12 birds. Treatments were: an unchallenged control (UC), a challenged (CC) control (0% DTB), and 3 challenged groups with 0.125, 0.25, or 0.5% DTB. At d 14, birds in the CC and DTB groups were orally gavaged with mixed Eimeria spp., while the UC received water. Growth performance was evaluated during prechallenge, challenge, and postchallenge periods (0-14 d; 14-20 d; and 20-26 d, respectively). Gastrointestinal permeability was measured at 5 days postinfection (dpi). Intestinal histology and nutrient digestibility of dry matter (DM), crude protein (CP), and ileal digestible energy (IDE) were measured at 6 dpi. Liver activity of glutathione peroxidase (GSH-Px) was determined at 6 dpi, and concentrations of reduced (GSH) and oxidized glutathione (GSSG) were analyzed at 6 and 12 dpi. Data were analyzed using a linear mixed model analysis and Tukey's test (P ≤ 0.05). From 0 to 14 d, similar average daily gain (ADG) and average daily feed intake (ADFI, P > 0.05) were observed. Gain:feed ratio (GF) was higher in 0.125, 0.25, and 0.5% of DTB than the CC and UC (P < 0.001). From 14 to 20 d, the UC had the highest ADG, ADFI, and GF (P < 0.001). At 5 dpi, intestinal permeability was higher in the challenged groups than the UC. Additionally, the UC showed the highest apparent ileal digestibility of CP, whereas 0.125% DTB had higher CP digestibility than the CC and 0.5% DTB (P < 0.001). At 6 dpi, 0.125% DTB increased GSH-Px activity compared to the CC, 0.5% DTB, and UC (P < 0.001). At 12 dpi, 0.125% DTB showed increased GSH concentration compared to the CC, 0.25% DTB, and 0.5% DTB (P < 0.01). The mild coccidia infection negatively impacted growth performance, apparent ileal nutrient digestibility, intestinal histology, and gastrointestinal integrity in broilers. The use of 0.125% DTB exhibited potential in improving antioxidant responses, apparent ileal digestibility of CP, and growth performance.

Oral impairments decrease the nutrient bioaccessibility of bread in the elderly

In the elderly, oral functions are modified by changes in muscular force or saliva production among others, resulting in inadequate food fragmentation which potentially impacts on oral and gastrointestinal digestion. The purpose of this work was to evaluate the consequences of oral deficiencies on the starch and protein digestibility of bread. In vitro boluses were prepared with the AM 2 masticator using normal and deficient mastication programming. Normal mastication (NM) and deficient mastication in terms of force (DfM), saliva (DsM), and their combination (DfsM) were performed. Static in vitro digestion, simulating physiological conditions in the elderly, were carried out. Bolus particle size, starch and protein digestibility, Fourier-transform infrared (FTIR) spectroscopy, and microstructure after in vitro oral and gastrointestinal digestion were analysed. More compacted boluses were observed after deficient mastication combined with greater particle sizes. The poorly fragmented boluses obtained with deficient mastication affected the oral digestion of starch, probably due to lower saliva impregnation. Digesta from deficient mastication boluses exhibited lower d -glucose release and degree of protein hydrolysis. FTIR results in the carbohydrates region also revealed weaker initiation of oral digestion of starch in DsM and DfsM boluses. These results on bread demonstrate for the first time how oral deficiencies modify nutrient bioaccessibility and, therefore, stress the importance of designing foods for specific populations such as the elderly. • Deficient mastication produces large particles limiting exchanges with saliva. • Oral starch digestion decreased in deficient masticated bread. • Intestinal starch and protein digestibility decreased in deficient masticated bread. • Protein hydrolysis' delay in GI tract is not explained by gluten secondary structure.

Effect of supplementing rumen-protected methionine, lysine, and histidine to low-protein diets on the performance and nitrogen balance of dairy cows

Lowering the dietary protein content can reduce N excretions and NH3 emissions from manure and increase milk N efficiency of dairy cows. However, milk yield (MY) and composition can be compromised due to AA deficiency. Methionine and Lys are known as first limiting EAA for dairy cows, and recently His is also mentioned as limiting, especially in grass-based or low-protein diets. To examine this, a trial was conducted with a 3-wk pre-experimental adaptation period (diet 16.5% crude protein), followed by a depletion period of 4 wk, in which 39 cows (average ± standard deviation: 116 ± 29.3 d in milk, 1.8 ± 1.2 lactations, 638 ± 73.2 kg of body weight, and 32.7 ± 5.75 kg MY/d) received a low-protein diet (CTRL) (14.5% crude protein). Then, taking into account parity, His plasma concentration, and MY, cows were randomly assigned to 1 of 3 treatment groups during the rumen-protected (RP) AA period of 7 wk; (1) CTRL; (2) CTRL + RP-Met + RP-Lys (MetLys); (3) CTRL + RP-Met + RP-Lys + RP-His (MetLysHis). Products were dosed, assuming requirements for digestible (d) Met, dLys, and dHis being, respectively, 2.4%, 7.0%, and 2.4% of intestinal digestible protein. In the cross-back period of 5 wk, all cows received the CTRL diet. During the last week of each period, a N balance was conducted by collecting total urine and spot samples of feces. Total feces production was calculated using the inert marker TiO2. Statistical analysis was performed with a linear mixed model with cow as random effect and data of the last week of the pre-experimental period used as covariate for the animal performance variables. No effect of supplementing RP-Met and RP-Lys nor RP-Met, RP-Lys, and RP-His on feed intake, milk performance, or milk N efficiency was observed. However, the plasma AA profile indicated additional supply of dMet, dLys, and dHis. Nevertheless, evaluation of the AA uptake relative to the cow's requirements showed that most EAA (exclusive Arg and Thr) were limiting over the whole experiment. Only dHis was sufficiently supplemented during the RP-AA period due to an overestimation of the diet's dMet and dLys supply in the beginning of the trial. The numerically increased milk urea N and urinary N excretion when RP-Met, RP-Lys, and RP-His were added to the low-protein diet suggest an increased catabolism of the excess His.

The path of proteolysis by bovine chymotrypsin

Chymotrypsin is one of the major proteases in intestinal protein digestion. Observations about the type of bonds that are hydrolysed (specificity and preference) were in the past derived from the peptide composition after digestion or hydrolysis rates of synthetic peptides. In this study, the path of hydrolysis by bovine chymotrypsin, i.e formation and degradation of peptides, were described for α-lactalbumin, β-lactoglobulin and β-casein. The peptide compositions, determined with UPLC-PDA-MS at different time points were used to determine the digestion kinetics for individual cleavage sites. It was evaluated how statements on (secondary) specificity from literature were reflected in the release kinetics of peptides. β-Lactoglobulin reached the highest degree of hydrolysis (10.9 ± 0.1 %) and was hydrolysed fastest (28 ± 1 mMpeptide bonds/s/mMenzyme), regardless of its globular (tertiary) structure. Chymotrypsin showed a preference towards aromatic amino acids, methionine and leucine, but was also tolerant to other amino acids. For the cleavage sites within this preference, ̴73% of the cleavage sites were hydrolysed with high or intermediate selectivity. For the missed cleavages within the preference, 45 % was explained by hindrance of proline, which affected hydrolysis only when in positions P3, P1′ or P2′. No clear indication (based on primary structure) was found to explain the other missed cleavages. A few cleavage sites were hydrolysed extremely efficient in α-lactalbumin (F9, F31, W104) and β-casein (W143, L163, F190). This study gave unique and quantitative insight in peptide formation and degradation by chymotrypsin in the digestion of proteins. The approach used showed potential to explore the path of hydrolysis for other proteases with less defined specificity.

Nutritional elucidation of rice- and maize gluten meal-based diets: in vitro gas production, digestibility, methane and rumen fermentation

This experiment intends to elucidate the nutritional potential of alternative ingredient – rice gluten meal (RGM) with groundnut cake (GNC) and maize gluten meal (MGM) at incremental levels in the complete diets under in vitro system. Nine complete diets were formulated using concentrate mixture, green maize and wheat straw in the ratio of 40:40:20 on a dry basis. The dietary treatments differed in the source of major protein sources used in three concentrate mixtures, i.e., GNC in control, while incremental levels of RGM and MGM – both at 25,50, 75 and 100% substituted GNC on an isonitrogenous basis. These diets were characterised for chemical composition, protein fractions, in vitro gas production profile as well as rumen fermentation attributes. The chemical composition of diets showed a mean crude protein (CP) and total digestible nutrient values of 12.9 and 63.6%, respectively. The range of values obtained for various CNCPS protein fractions (% CP) was 11.3-12.4, 9.42-14.0, 40.9-44.4, 19.1-20.1 and 13.6-15.9 for PA, PB1, PB2,PB3 and PC, respectively across the diets. Furthermore, rumen undegradable protein was maximum at 100% MGM inclusion and least for the control. However, intestinal protein digestibility did not differ due to treatments. While the GV24 was maximum (P&lt;0.01)in the control, it was lowest at 100% MGM. Additionally, in vitro dry matter and organic matter digestibilities were higher (P&lt;0.01)for 100% MGM diet and lowest (P&lt;0.01) at 100% RGM level. Moreover, the control diet generated maximum (P&lt;0.01) CH4 but was minimum (P&lt;0.01) for 100% MGM diet. The values of PF,MBP and MBP:GV24 were highest(P&lt;0.01) for 100% MGM and lowest (P&lt;0.01) for control diet. The pH of rumen fluid did not differ; however, concentrations of ammonia nitrogen and total volatile fatty acids were recorded to be maximum (P&lt;0.01) in controland minimum (P&lt;0.01) at 100% MGM. Further, the molar concentration of acetic acid was higher (P&lt;0.01) with MGM-based diets than that of control and RGM diets. Lastly, the proportions of both propionic and butyric acids were minimumwith MGM-based diets than with either control or RGM-baseddiets. Therefore, it could be recommended that RGM could substitute 50-75% of GNC, corresponding to 5-8% inclusion in the complete diet of ruminants. In addition, MGM-based diets excelled in terms of greater digestibility, reduced CH4 emission as well as beneficially influenced rumen fermentation

Use of Heating Methods and Xylose to Increase Rumen Undegradable Protein of Alternative Protein Sources: 1) Peanut Meal

Peanut meal has an excellent total protein content but also has low rumen undegradable protein (RUP). High-performance ruminants have high RUP requirements. We aimed to evaluate the effects of processing peanut meal with an autoclave and conventional and microwave ovens, with and without using xylose on its ruminal kinetics degradation parameters and intestinal digestibility (ID). In situ studies were conducted to determine dry matter (DM) and crude protein (CP) rumen degradation kinetics. In vitro studies were conducted to evaluate intestinal digestibility (ID). The control treatment had a greater fraction A for DM and CP than peanut meals processed with an autoclave or conventional oven. The control had greater kd for CP compared with the microwave. The addition of xylose decreased fraction A, the degradation rate of fraction B (kd) and RUP, and increased the protein B fraction of autoclaved peanut meal. We observed a decrease in effective degradability (ED) and increased RUP for processed treatments in all experiments compared with the control. Processing methods did not affect the protein ID of autoclaved peanut meal compared to the control. An interaction between xylose and heating time was observed, where increasing heating time linearly reduced the ID of xylose-untreated treatments. Overall, these results suggest that the tested methods effectively increased the RUP content of peanut meal.

Emerging polyfluorinated compound Nafion by-product 2 disturbs intestinal homeostasis in zebrafish (Danio rerio)

Nafion by-product 2 (Nafion BP2), an emerging fluorinated sulfonic acid commonly used in polymer electrolyte membrane technologies, has been detected in various environmental and human matrices. To date, however, few studies have explored its toxicity. In this study, zebrafish embryos were exposed to Nafion BP2 at concentrations of 20, 40, 60, 80, 100, 120, 140, and 160 mg/L from fertilization to 120 post-fertilization (hpf), and multiple developmental parameters (survival rate, hatching rate, and malformation rate) were then determined. Results showed that Nafion BP2 exposure led to a significant decrease in survival and hatching rates and an increase in malformations. The half maximal effective concentration (EC50) of Nafion BP2 for malformation at 120 hpf was 55 mg/L, which is higher than the globally important contaminant perfluorooctane sulfonate (PFOS, 6 mg/L). Furthermore, exposure to Nafion BP2 resulted in additional types of malformations compared to PFOS exposure. Pathologically, Nafion BP2 caused abnormal early foregut development, with exfoliation of intestinal mucosa, damage to lamina propria, and aberrant proliferation of lamina propria cells. Nitric oxide content also decreased markedly. In addition, embryos showed an inflammatory response following Nafion BP2 exposure, with significantly increased levels of pro-inflammatory factors C4 and IL-6. Acidic mucin in the hindgut increased more than two-fold. 16 S rRNA sequencing revealed a marked increase in the pathogen Pseudomonas otitidis. Furthermore, pathways involved in intestinal protein digestion and absorption, inflammatory response, and immune response were significantly altered. Our findings suggest that the intestine is a crucial toxicity target of Nafion BP2 in zebrafish, thus highlighting the need to evaluate its health risks.