Digestion Tests Research Articles

Pengaruh Penambahan Spirulina platensis sebagai Sumber Protein Nabati pada Daging Analog bagi Vegetarian

Spirulina platensis is a vegetable protein source that may improve the quality of food product. The objective of this study was to determine the effect of addition S. platensis on analog meat at concentrations of 0, 10, 20, and 30% and to determine the best concentration of addition S. platensis on meat analogs preferred by the panelists. The processing of meat analogs used steaming method at 100°C for 30 minutes. The researched method applied a completely randomized design. The analog meat samples were analyzed in terms of protein content, protein digestibility, moisture content, texture, color, and hedonic tests. The highest protein content and protein digestibility was at concentrations of S. platensis 30%, 32.24 and 62%. The moisture content obtained at 30% concentration was 54.70%, and the texture at 30% concentration was 1.53 N which resembles the texture of animal meat. Analog meat preferred by panelist was at concentration of 20% which had a texture preference of score of 6.33; aroma 5.00 and taste 6.33 from the average 30 panelist score and had a confidence interval value of 5.56<µ<6.22.

Decrease of Greenhouse Gases during an In Vitro Ruminal Digestibility Test of Forage (Festuca arundinacea) Conditioned with Selenium Nanoparticles.

The Festuca arundinacea Schreb. is one of the most used forage grasses due to its duration, productivity, great ecological breadth, and adaptability. Livestock has been criticized for its large production of greenhouse gases (GHG) due to forage. The advancement of science has led to an increase in the number of studies based on nanotechnologies; NPs supplementation in animal nutrition has found positive results in the fermentation of organic matter and the production of fatty acids and ruminal microorganisms. The objectives of this study were (1) to evaluate the in vitro digestibility of forage containing selenium (Se) nanoparticles (NPs), and to identify the specific behavior of the ruminal fermentation parameters of F. arundinacea Schreb. and (2) quantify the production of greenhouse gases (total gas and methane) (3) as well as the release of bioactive compounds (phenols, flavonoids, tannins, and selenium) after fermentation. Three treatments of SeNPs were established (0, 1.5, 3.0, and 4.5 ppm). The effects of foliar fertilization with SeNPs son digestion parameters were registered, such as the in vitro digestion of dry matter (IVDM); total gas production (Atotal gas) and methane production (ACH4); pH; incubation time(to); the substrate digestion rate (S); tSmax and the lag phase (L); as well as the production of volatile fatty acids (VFA), total phenols, total flavonoids, and tannins in ruminal fluid. The best results were obtained in the treatment with the foliar application of 4.5 ppm of SeNPs; IVDMD (60.46, 59.2, and 59.42%), lower total gas production (148.37, 135.22, and 141.93 mL g DM-1), and CH4 (53.42, 52.65, and 53.73 mL g DM-1), as well as a higher concentration of total VFA (31.01, 31.26, and 31.24 mmol L-1). The best results were obtained in the treatment with the foliar application of 4.5 ppm of SeNPs in the three different harvests; concerning IVDMD (60.46, 59.2, and 59.42%), lower total gas production (148.37, 135.22, and 141.93 mL g DM-1), and CH4 (53.42, 52.65, and 53.73 mL g DM-1), as well as a higher concentration of total VFA (31.01, 31.26, and 31.24 mmol L-1). The F. arundinacea Schreb. plants fertilized with 4.5 ppm released-in the ruminal fluid during in vitro fermentation-the following contents: total phenols (98.77, 99.31, and 99.08 mgEAG/100 mL), flavonoids (34.96, 35.44, and 34.96 mgQE/100 g DM), tannins (27.22, 27.35, and 27.99 mgEC/100g mL), and selenium (0.0811, 0.0814, and 0.0812 ppm).

Formation and characteristics of curcumin-loaded binary gels formed from large yellow croaker (Pseudosciaena crocea) roe protein isolate and gellan gum

The aim of this study was to investigate the effect of gellan gum (GG) on the cold gelation of large yellow croaker roe protein isolate (pcRPI). The water-holding ability and storage modulus of the pcRPI-GG binary gels increased with the GG concentration, where the storage modulus of the pcRPI-0.2% GG gel was approximately 30.7 times that of the pure pcRPI gel. Compare to the other binary gels, pcRPI-0.2% GG gels exhibited a lower lacunarity and higher junction density, with a denser, more aggregated microstructure. Consequently, curcumin was embedded in pcRPI-0.2% GG gels, and simulated gastrointestinal digestion test results showed that GG addition effectively protected and slowed curcumin release in the gastrointestinal environment. These findings may contribute to elucidating the interaction of pcRPI with GG and demonstrate the potential of binary gels for the embedding and delivery of active substances.

Release kinetics and encapsulation efficiency of embedded active ingredients in fat-based matrices using cold extrusion

Cold extrusion offers great potential as a continuous and gentle encapsulation technique. Due to their melting and crystallization properties, lipids are ideal matrix materials as they can be influenced by extrusion process parameters, such as temperature and shear. This offers the possibility to develop various lipid-based matrix materials with specific release properties, ensuring a delayed release during gastrointestinal digestion. The objective of the present work was a methodical physicochemical characterization of cold extruded fat matrices serving as matrix material for the embedding of 10% beetroot powder, which was used as model active agent due to its detectability by photometric measurement. The matrices were composed of a high-melting fully hydrogenated rapeseed oil as the base fat and one of four low-melting fats/oils. By performing a semi-dynamic in vitro digestion test, physicochemical characteristics of fat-based matrices were investigated. The influence of release properties and encapsulation efficiency of encapsulated beetroot powder were identified. The results showed that the matrix composition influences, particle size distribution, melting behavior and microstructural fat distribution. Melting behavior and solid fat content proved to be determinant properties influencing the release behavior – especially, the deviation of solid fat contents in the temperature range from room (20.0 °C) to body temperature (36.5 °C) during in vitro digestion. Generally, a higher content of low-melting fat led to an increased release of beetroot powder during the intestinal phase of up to 48%, whereas only 3.3% on average were released during oral and gastric phase each. Microstructural analysis showed that melting properties are also influenced by the time factor as a temporal delayed release of beetroot powder was determined.

Mechanistic Understanding of the Relationships between Structure and Digestibility of Octenyl Succinic Anhydride Modified Corn, Potato, and Pea Starch Nanoparticles

AbstractThis study characterizes the digestibility properties and structural changes of octenyl succinic anhydride (OSA) modified starch nanoparticles (OSPNs) from corn, potato, and pea starches (codes as OCSNPs, OPtSNPs, and OPSNPs). After OSA modification, the average particle size and degree of substitution of OSPNs significantly (p < 0.05) increase compared to control samples, whereas the apparent amylose content, R1047/1022, relative crystallinity, and melting enthalpy are found to decrease significantly (p < 0.05), with the extent depending on the type of starch. In vitro digestibility tests show that OSA treatment converts part of rapidly digestible starch into slowly digestible starch and resistant starch for OSPNs, an effect that is more pronounced for OPtSNPs compared to OCSNPs and OPSNPs, corresponding to a reduce in equilibrium starch hydrolysis percentage and apparent digestion rate coefficient. Overall, the starch type affects the structural and digestibility properties of OCSNPs, OPtSNPs, and OPSNPs, with the most obvious effect observes for OPtSNPs.

What Is the Right Rate? Determining Digestibility Kinetics of Pretreated Waste Activated Sludge During Anaerobic Digestion

Pretreatment of municipal sludge has the potential to improve anaerobic digestion by increasing the ultimate biodegradability of particulate chemical oxygen demand (PCOD) to methane (CH4) gas. However, the effect of pretreatment, that is, increased soluble COD from solubilization of PCOD, makes it difficult to correctly estimate hydrolysis kinetics in biochemical methane potential tests. In this study, batch digestion tests were used to evaluate the general impact of alkaline and thermal pretreatment of waste activated sludge (WAS) and to determine a different method to estimate hydrolysis rates from pretreated streams. Throughout the 60-day batch experiments, liquid and gas samples were collected and analyzed for total (TCOD) and semi-soluble (SSCOD) COD, total (TSS) and volatile (VSS) suspended solids, pH, volatile fatty acids (VFAs), and ammonium concentration. Pretreatments significantly decreased VSS concentrations at the start of digestion, but all samples showed similar VSS destruction to the control at the end of the experiments. Ultimate CH4 production was significantly increased by alkaline and thermal pretreatments, which produced 203 and 219 mL CH4 gVSS−1, respectively, versus 175 mL CH4 gVSS−1 in the control. Although CH4 generation was a good proxy for solids hydrolysis of untreated WAS, CH4 generation significantly overestimated the rate of hydrolysis of pretreated solids. The overestimation was due to the abundance of SSCOD available at the start of the experiment being converting to CH4. Incorporating SSCOD or VFAs into the hydrolysis kinetics resulted in much slower hydrolysis rates that were similar to those measured by VSS destruction directly (e.g., 0.08 d−1 with SSCOD + CH4 vs. 0.19 d−1 from CH4 alone for thermal pretreatment vs. 0.05 d−1 with VSS alone). The slower kinetics indicate that the necessity to understand the trade-offs between the performance advantages of pretreatment (i.e., solids destruction and energy conversion) versus the operational and financial impacts on large-scale digestion.

Soy protein-based delivery systems as carriers of trans-resveratrol: Bioaccessibility using different in vitro digestion models

Ingestion of trans-resveratrol promotes health benefits, but the low solubility and chemical stability of this compound may hamper its bioaccessibility. To overcome these drawbacks, O/W emulsions loaded with resveratrol (liquid or gelled) and stabilized by soy protein isolate (SPI) were used to protect and vehiculate the bioactive compound to the target absorption site. Two distinct strategies were used to allow protein denaturation: heating the A) aqueous phase of the emulsion before homogenization; or B) emulsion after homogenization. Delivery efficacy of resveratrol was evaluated by static or semi-static in vitro digestion assays. For the semi-static approach, a dynamic gastric model was developed that was able to simulate the intensity of contraction forces and the gradual decrease of pH in the gastric step in vivo. The structure of the liquid emulsions remained similar in the static and semi-static digestion approaches, showing little influence of peristalsis on droplet size. The gelled emulsions showed breakdown of the gel network in the presence of the mechanical forces of the semi-static tests, although its structure was not completely degraded at the end of the in vitro digestibility tests. Anyway, the results of bioaccessibility of the carriers were similar (around 70–75%) and high, being these emulsions effective carriers of resveratrol. However, the bioaccessible fraction of liquid emulsions was much higher after digestion under static conditions, showing the relevance of developing dynamic systems for a more realistic simulation of in vitro digestion processes.

Study on Structural and Physicochemical Properties of Modified Corn Starch: Comparison of Ultrasound, Stirring, and Lactic Acid Treatments

AbstractUltra‐sonication has been growingly utilized in starch modification as a green and non‐thermal technology. In this research, the effect of ultrasonic, stirring, and lactic acid treatments alone and with their combination (binary and ternary) on the properties and structure of corn starch is investigated. In the ternary treatment, degree of substitution of lactate on the polymeric chains of the starch is increased, inducing an esterified structure, which imparted to the modified starch a higher swelling power, water holding capacity, water absorption index, oil absorption rate, and amylose content along with lower viscosity and activation energy of gelatinization than native starch and the rest of the treatments. Also, the in vitro starch digestibility test with ternary treatment exhibits lowest rapidly digestible starch fraction, and highest slowly digestible starch and resistant starch fractions. The XRD patterns demonstrate a reduction in crystallinity percentage of the modified starch by the ternary treatment compared to native starch. The images of SEM indicate that ultra‐sonication and acid hydrolysis result in the damage of granules' surface, while sample agitation by stirring causes no change. Esterification of corn starch is proved by FT‐IR. Starch modification by the proposed ternary treatment can be utilized in production of low‐calorie foods.

Integration of sludge ozonation with anaerobic digestion: From batch testing to scenario analysis with energy, economic and environmental assessment

A methodological procedure, based on results from batch experiments, is proposed and applied to a selected wastewater treatment plant generating a poorly degradable sludge, to identify the best configuration and ozone dosage for full-scale application of sludge ozonation. Samples of pre-thickened and digested sludge were collected, tested at different ozone dosages and characterized to gather useful data for energy, economic and carbon footprint balances. The most viable scenario was found to be sludge pre-treatment at the lowest tested dosage (20 mg O3/g VS), yielding energy, cost and GHG emission net savings of 177 MWh/y, 57.8 k€/y and 6.38 Mg CO2-eq./y, respectively. Sensitivity analyses, conducted by varying the specific energy required for ozone generation and the unit costs for sludge disposal and resource supply, confirmed the stability of this scenario, whereas a field pilot-scale testing is advisable to verify modified process conditions for a safe and efficient application of sludge ozonation. The proposed methodology, including laboratory batch anaerobic digestion tests, scenario definition and energy/economic/environmental balances, could be preliminary applicable to all situations to broadly analyze all involved aspects and give a useful overview about the effective applicability of sludge ozonation.

Effective and simultaneous removal of heavy metals and neutralization of acid mine drainage using an attapulgite-soda residue based adsorbent

Implementing an economical and effective measure for treating acid mine drainage (AMD) from abandoned mines using low-cost restoration reagents present a significant challenge. In this study, natural attapulgite (AT) and soda residue (SR) composite particles (AT-SR) were firstly prepared and utilized in AMD treatment. The efficiencies and mechanisms of AT-SR composites for regulating acidity and removing metals in AMD, the critical factors influencing the treatment efficiencies, and the regeneration performance and environmental risk were investigated. It is illustrated that AT and SR quality ratio of 5:5, dosage of 0.5 g L−1, particle size < 1.5 mm, concentrations of 150 mg L−1 for Fe, 75 mg L−1 for Mn and 100 mg L−1 for Cu, Zn, Cd and Pb, and adsorption time of 120 min were the optimized conditions. The maximum adsorption capacities of Fe, Mn, Cu, Zn, Cd and Pb under single metal scenarios were 51.61, 22.30, 37.05, 40.21, 37.39 and 49.53 mg g−1, respectively. Under the mixed metal scenarios, competitive adsorption was predominated with the rate constants in the reducing order of 3.169 for Fe > 0.841 for Cu > 0.657 for Pb > 0.083 for Zn > 0.024 for Cd > 0.006 for Mn. The experimental data was fitted well with the pseudo-second-order and the Freundlich isotherm models. AT-SR is an outstanding neutralizer for AMD due to its richness in calcium and magnesium oxides and the spent AT-SR composites could be easily regenerated while maintaining high metal removal efficiencies under the subsequent usages. It is determined under the aqua regia digestion and Toxicity Characteristic Leaching Procedure (TCLP) tests that AT-SR can be used safely without posing environmental risks, thus promoting the resource recovery and utilization of soda residue and providing a green and effective method for treating AMD.

Exploring the performance of amaranth grain starch and protein microcapsules as β-carotene carrier systems for food applications

Underexploited sources of bio-based wall materials for bioactive compounds (such as β-carotene) encapsulation have gained increasing interest within the scientific community. In this study, the potential of amaranth (Amaranthus cruentus) grain starch and protein rich fractions as microcapsules’ wall materials to carrier β-carotene was evaluated. Microcapsules were produced by spray-drying and their morphological and physicochemical characterisation was carried out. The microcapsules presented a spherical shape (particle size distribution: 0.3–30 µm) and encapsulation efficiencies ranging from 64 % to 69 %. Results showed that protein-based microcapsules had better β-carotene storage stability as compared to starch-based microcapsules (at 8 and 25 °C). β-carotene release kinetics at 37 °C and pH 7.4 could be mainly described by structural-relaxation phenomenon using the linear superposition model. Moreover, encapsulated β-carotene exhibited higher bioaccessibility than its free form after simulated in vitro digestion tests. Microcapsules did not affect cell viability at 0.0625 mg L−1 of β-carotene. Thus, amaranth grain biopolymers-based microcapsules were successfully developed as promising β-carotene delivery systems to be added to food products and consequently, to improve their functionality.

A low-cost system for the study of proteins used in salmonid diets, use of proteolysis to determine the quality

A proteolysis system, a classic biochemistry model, is proposed to enable the feasibility of indirectly assessing the quality of protein present in salmonid diets like screening system. An artificial gastric solution was developed with pepsinogen commercial, the volume of a salmonid stomach was estimated, and 8 g of food was mixed per 50 ml of solution, which was constantly stirred for 3 h and kept at 15 °C constant. We note that this artificial gastric solution requires pepsin to degrade samples, which occurs at pH 2.0, in addition, proteolysis depends on time and temperature. Comparing albumin, food and a standard mixture of proteins could observe varying degrees of fragmentation. The results suggest a low-cost system to evaluate the source of a protein, by correlated the number of fragments generated, an indicator of the quality of the protein. In addition, it allows evaluating mixtures with the disposition of the protein to be proteolyzed. The present protocol can be used for screening protein before to in vivo test and after of digestibility test or in support of digestibility protocol for improve nutrition study.

Digestibility and Nutritional Value of Fermented Straw Supplemented with Green Concentrate as Feed Ingredients for Holstein Friesian Dairy Cattle

The purpose of this study was to determine the effect of fermented straw supplementation with green concentrate on nutrient content and nutrient digestibility. Green concentrate used as treatment was white lead tree leaf flour ( Leucaena leucocephala ), Gamal leaf meal ( Gliricidia sepium ), and Indigofera leaf meal. Proximate analysis was carried out on fermented rice straw, 70% fermented rice straw + 30% lamtoro (FRS + white lead tree), 70% fermented rice straw + 30% Gamal (FRS + Gamal ) and 70% fermented rice straw + 30% Indigofera (FRS + Indigofera ). The livestock used for the nutrient digestibility test was 12 Friesian Holstein dairy cows. A randomized block design was used to test nutrient digestibility. The results showed that supplementation of green concentrate in fermented rice straw was able to increase crude protein, crude fat, and BETN and decrease crude fiber. Crude protein digestibility did not differ in the three types of green concentrates. Crude fat digestibility of FRS + white lead tree and FRS + Indigofera was higher than FRS + Gamal . The digestibility of BETN FRS + Gamal was higher than the digestibility of FRS + white lead tree and FRS + Indigofera . This study concludes that the three types of green concentrate can be used for the supplementation of fermented rice straw as dairy cattle feed.

Fluorescence turn-on probes for intracellular DNA/RNA distribution based on asymmetric bis(styryl) dyes

Two bis(styryl) dyes, varying in type of spacer between two mono(styryl) units, were tested for interactions with ct-DNA or cl-RNA. Both compounds showed strong affinity toward ds-DNA/ss-RNA, the binding mode of the interaction is shifting between DNA groove binding to RNA intercalation. Consequently, interaction with DNA shows a stronger flare-up of fluorescence (151 times for dye 1 and 118 times for dye 2) than when binding with RNA (23 times and 36 times correspondingly). The presence of energy transfer in the bis(styryl) system increases the Stokes shift of the dye, so when irradiating the system in the region of 370–380 nm, fluorescence is detected at 610–620 nm. The biological experiments showed that the efficient intracellular fluorescence quench was observed in the DNase digest test suggested that dyes can be applied by recognition of DNA in the presence of RNA molecules.

Glycosylation of Semi-Synthetic Isoflavene Phenoxodiol with a Recombinant Glycosyltransferase from Micromonospora echinospora ATCC 27932.

Glycosyltransferase (GT)-specific degenerate PCR screening followed by in silico sequence analyses of the target clone was used to isolate a member of family1 GT-encoding genes from the established fosmid libraries of soil actinomycetes Micromonospora echinospora ATCC 27932. A recombinant MeUGT1 was heterologously expressed as a His-tagged protein in E. coli, and its enzymatic reaction with semi-synthetic phenoxodiol isoflavene (as a glycosyl acceptor) and uridine diphosphate-glucose (as a glycosyl donor) created two different glycol-attached products, thus revealing that MeUGT1 functions as an isoflavonoid glycosyltransferase with regional flexibility. Chromatographic separation of product glycosides followed by the instrumental analyses, clearly confirmed these previously unprecedented glycosides as phenoxodiol-4'-α-O-glucoside and phenoxodiol-7-α-O-glucoside, respectively. The antioxidant activities of the above glycosides are almost the same as that of parental phenoxodiol, whereas their anti-proliferative activities are all superior to that of cisplatin (the most common platinum chemotherapy drug) against two human carcinoma cells, ovarian SKOV-3 and prostate DU-145. In addition, they are more water-soluble than their parental aglycone, as well as remaining intractable to the simulated in vitro digestion test, hence demonstrating the pharmacological potential for the enhanced bio-accessibility of phenoxodiol glycosides. This is the first report on the microbial enzymatic biosynthesis of phenoxodiol glucosides.

Ovalbumin-Induced Allergic Inflammation Diminishes Cross-Linked Collagen Structures in an Experimental Rabbit Model of Corneal Cross-Linking.

BackgroundAllergic conjunctivitis (AC) is one of the reported potential risk factors of progression in keratoconus patients after corneal cross-linking surgery; however, the causal relationship is still inconclusive. Recent studies have indicated that various inflammatory cytokines play a vital role in the development of primary keratoconus. It is still unclear whether these inflammatory mediators also trigger CXL failures. This study aimed to investigate the impact of AC on the rabbit corneas after trans-epithelial corneal cross-linking (TCXL).MethodsA total of six rabbits were kept untreated as the normal control (NC) group. A total of 18 rabbits were treated by TCXL and divided into three groups (six in each group), namely, no treatment (TCXL group); induction of AC (TCXL + AC group); and induction of AC plus topical prednisolone acetate (TCXL + AC + PA group), according to additional treatment. AC was induced by topical application of ovalbumin after intraperitoneal pre-sensitization with ovalbumin. Rabbits were evaluated by slit lamp, in vivo laser scanning confocal microscopy, anterior segment optical coherence tomography, and measurement of corneal biomechanics. The cornea specimens were collected for the transmission electron microscope, the collagenase I digestion test, and PCR assay for TNF-α, IL-6, IL-1β, matrix metalloproteinase 9 (MMP-9), lysyl oxidase (LOX), and tissue inhibitor of metalloproteinases 1 (TIMP-1) on the day (D) 28.ResultsOn D28, the TNF-α, IL-6, IL-1β, MMP-9, and LOX levels were significantly increased while the TIMP-1 was decreased in the TCXL + AC group when compared with the TCXL and TCXL + AC + PA groups. In vivo confocal microscopy revealed that at a depth of 150–210 μm, a trabecular patterned hyperdense structure surrounded by elongated needle-like processes could be observed in the TCXL and TCXL + AC + PA groups, but hardly seen in the TCXL + AC group. The demarcation lines were indistinct and blurred in the TCXL + AC group. An electron microscope demonstrated less interlacing fibril lamellae and higher interfibrillar spacing in the TCXL + AC group. The stability of corneal biomechanics and resistance to collagenase were decreased in the TCXL + AC group.ConclusionThe corneal microstructures induced by TCXL and biomechanical stability were diminished in rabbits with AC but could be maintained by topical anti-inflammatory treatment. Our results supported the causal relationship between altered cytokine profiles and corneal microstructure after primary corneal cross-linking.

The first insight into black soldier fly meal in brown trout nutrition as an environmentally sustainable fish meal replacement

Insect meals are considered among the most promising feed materials in fish nutrition due to their sustainability and possibility of fish meal replacement. The present study is the first application of full-fat black soldier fly larvae (BSFL) meal in brown trout (Salmo trutta m. fario) diets. Two experiments were performed on 240 brown trout fingerlings (average body mass 4.85 g) distributed into four groups (12 tanks for the growth performance experiment, 10 fish/tank; and 12 metabolic tanks for the digestibility test, 10 fish/tank). The experimental group design was conducted as follows: control diet, with no BSFL and 35% fish meal, and experimental diets: BSFL5 – with 5% BSFL full-fat meal and 32.5% fish meal; BSFL10 – with 10% BSFL full-fat meal and 30% fish meal; and BSFL20 – with 20% BSFL full-fat meal and 25% fish meal. No effects were recorded in the case of growth performance and feed utilization parameters. The environmental sustainability of the usage of insect meals in fish diets was proven – due to the lower fish meal inclusion, the fish-in-fish-out ratio decreased by 31% in BSFL20. In the case of the viscerosomatic index, increases in BSFL5 and BSFL20 were reported. In all experimental groups, decreases in hepatosomatic index values were observed. Crude protein digestibility decreased in BSFL5 and BSFL20, while crude fat digestibility decreased only in the BSFL20 group. The effect of including BSFL full-fat meal in a brown trout diet on serum biochemical parameters was reported. The aspartate transaminase concentration increased in BSFL10 and BSFL20, while the gamma-glutamyl transpeptidase values decreased in BSFL20. In the case of total cholesterol, higher values were observed in BSFL10 and BSFL20. The albumin content decreased in the BSFL20 group, while globulin showed the highest values in the control group. The microbiota composition was not affected by insect meal inclusion. In conclusion, the results of the present study showed the high potential of BSFL full-fat meal application of up to 20% in a brown trout diet.

Preparation of Natural Food-Grade Core-Shell Starch/Zein Microparticles by Antisolvent Exchange and Transglutaminase Crosslinking for Reduced Digestion of Starch.

The purpose of this study was to slow down the digestibility of starch granules by encapsulating it in zein shells. Drop of the preformed swollen corn starch (CS) granule suspension into thermal-treated zein ethanolic solution enables antisolvent precipitation of thermal-treated zein on the surface of the preformed swollen CS granules, leading to the formation of core-shell starch/zein microparticles. Confocal laser scanning microscopy images showed that the preformed swollen CS granules were coated by thermal-treated zein shells with a thickness of 0.48–0.95 μm. The volume average particle diameter of core-shell starch/zein microparticles was 14.70 μm and reached 18.59–30.98 μm after crosslinking by transglutaminase. The results of X-ray diffraction and Fourier transform infrared spectroscopy demonstrated that an interaction occurred between the preformed swollen CS granules and the thermal-treated zein. The results for thermodynamic characteristics, pasting properties, and swelling power indicated that the compact network structure of core-shell starch/zein microparticles crosslinked by transglutaminase could improve starch granule thermal stability and resistance to shearing forces. Compared to native CS, the peak gelatinization temperatures of core-shell starch/zein microparticles increased significantly (p < 0.05), with a maximum value of 76.64°C. The breakdown values and the swelling power at 95°C of core-shell starch/zein microparticles significantly (p < 0.05) decreased by 52.83–85.66% and 0.11–0.28%, respectively. The in vitro digestibility test showed that the contents of slowly digestible starch and resistant starch in the core-shell starch/zein microparticles increased to ∼42.66 and ∼34.75%, respectively, compared to those of native CS (9.56 and 2.48%, respectively). Our research supports the application of food-grade core-shell starch/zein microparticles to formulate low-digestibility food products.

A comprehensive evaluation of process kinetics: A plant-wide approach for nutrient removal and biogas production

The present study investigated the deviations of operational parameters of a large-scale wastewater treatment plant (WWTP) from design basis through combining dedicated batch experiments with full-scale dynamic modeling results. The long-term process performance of a full-scale biological nutrient removal (BNR) plant equipped with anaerobic sludge digestion system was monitored to evaluate the process kinetics of both carbon and nutrient removal and anaerobic sludge digestion. In this respect, plant-specific characterization; chemical oxygen demand (COD) fractionation, batch kinetic studies and sludge settling velocity tests were performed together with plant-wide SUMO model simulation. Results showed that nitrification and anaerobic hydrolysis were found to be 30% and 70% lower than literature values, respectively. The anaerobic digestion test coupled with plant-wide model calibration showed that anaerobic hydrolysis was the bottleneck in biogas production. Correspondingly, performance of the anaerobic digestion in the full-scale plant was poor as low biogas production yields were observed. In addition, the degradation rate via anaerobic hydrolysis of primary sludge was found to be higher (∼2-2.5) compared to anaerobic hydrolysis of biological sludge. The results of this study provide insight into model-based experimental characterization as well as plant-wide modeling approach. Coupling model-based batch experiments with full-scale modeling enabled to reduce the number of kinetic parameters to be fine-tuned. Moreover, the information gathered from kinetic batch tests to the simulation platform yielded a satisfying prediction of long-term performance of the plant operation.

Effect of Heating Time of Cottonseed Meal on Nutrient and Mineral Element Digestibility in Chicken (Based on Cottonseed Meal Replaced with All Soybean Meal).

Simple SummaryAt present, we are faced with the problem of a feed protein resource shortage. Cottonseed meal is a potential alternative protein source for use in poultry diets. High-temperature treatment is a common processing method of cottonseed meal. Our experiment was conducted to estimate the effects of heating time of cottonseed meal on nutrient digestibility and mineral element absorption of chicken.A digestibility test was conducted to estimate the effects of the heating time of cottonseed meal on nutrient digestibility and mineral element absorption in chicken. A total of 36, 45-week-old healthy New Yangzhou chickens with similar body weight were randomly divided into 6 groups with 6 replicates per group and one chicken per replicate. The chickens in Group A (control group) were fed the corn-soybean meal diet. The chickens in Groups B, C, D, E, and F (experimental groups) were fed the cottonseed meal to replace all soybean meal. The cottonseed meal in the experimental groups was treated with wet heating. The heating temperature was set at 120 °C, and the humidity was set at 50%. The heating time was set to 10, 15, 20, 25, and 30 min successively. The trial period was 4 day. The digestibility of crude protein, metabolic energy, and dry matter was highest using wet-heat treating for 15 min (p < 0.05). The digestibility of Fe increased significantly from 66.78% to 70.39% when the heating time of cottonseed meal was prolonged from 10 min to 30 min (p < 0.05). Compared with Group A, the digestibility of Zn was increased in Groups B and C, and then there was a decrease in Group D. Finally, the digestibility was increased again in Group F. The opposite pattern was shown in the digestibility of Cu and Zn. There was no significant effect of wet heat treatment time on the digestibility of calcium, phosphorus, and manganese (p > 0.05). When cottonseed meal is considered as feed for 45-week-old chickens, processing conditions of 120 °C and 50% humidity for 15 min are recommended.