Indigestible Fraction Research Articles

Polyenzyme preparations in feeding of monogastric animals

In animal feeding enzyme preparations are mainly used, which are not produced in the body of animals, although in chickens in the first weeks of life and piglets after weaning an insufficient amount of their own proteases and amylases is formed, so their inclusion in feed is also useful. By now highly active enzyme preparations with various specific activities have been created and are being produced. In feeds prepared using traditional raw materials up to 30% of nutrients are not available for digestion by enzymes secreted in the gastrointestinal tract. The inclusion of exogenous enzymes in the feed provides additional use of the indigestible fraction. It is impossible to achieve complete digestibility of feed, although in vitro exogenous enzymes digest almost 100% of the target substrates. The problem is due to the fact that natural feed does not contain pure substrates — they are associated with other substances that limit the availability of enzymes to them. The properties of natural substrates, their concentration and availability even in the same raw material are variable, which excludes reliable prediction of the effectiveness of the action of feed enzymes. Partially these difficulties are overcomed by the use of polyenzyme drugs. It is necessary to further study the specificity of native substrates and factors that increase their availability for the action of enzymes.

A simplified model for simulating anaerobic digesters: Application to valorisation of bagasse and distillery spent wash

Current anaerobic digestion (AD) design methods rely on crude empirical models or sophisticated anaerobic digestion models (like ADM1) requiring a large number of parameters which are difficult to obtain experimentally. A simplified model for simulating AD was developed in this work. The model requires knowledge of CH4/CO2 ratio in biogas or indigestible fraction in substrate and batch biomethane potential (BMP) data for estimating three kinetic parameters (maximum specific growth rate, half velocity constant and cell death rate). Reported lab scale BMP data of sugarcane bagasse and spent wash were used to first estimate the kinetics and then to simulate corresponding largescale AD. Simulated results of specific methane yield and digester performance were consistent with available largescale AD data. The potential of the model to simulate single and multi-stage AD were illustrated. The presented approach and model will be useful for effectively valorising a variety of complex biomass substrates to biogas.

In vitro gastrointestinal digestion and colonic fermentation of tomato (Solanum lycopersicum L.) and husk tomato (Physalis ixocarpa Brot.): Phenolic compounds released and bioconverted by gut microbiota

Two of the most important Mexican plant-foods are tomato (Solanum lycopersicum L.) and husk tomato (Physalis ixocarpa Brot.). In this study three objectives were followed: i) to evaluate the bioaccessible phenolic compounds (PC) in T and HT during upper gastrointestinal digestion, ii) to in vitro ferment the indigestible fractions of the samples to evaluate the short-chain fatty acids (SCFA) production, iii) the microbial metabolites, bioconverted PC and volatile organic compounds (VOCs) generated during the fermentation. Vanillic acid was the most bioaccessible PC and after 48 h, 3-hydroxyphenylacetic acid was the most abundant microbial metabolite identified in both samples. The identification of VOCs belonging to terpenes (and derivatives) group in T and HT can be product of the microbial metabolism of carotenoids. The study shows new knowledge of the in vitro intestinal digestion and fermentation of T and HT final compounds with biological potential which should be evaluated in further studies.

Phenolic compounds from ‘Hass’ avocado peel are retained in the indigestible fraction after an in vitro gastrointestinal digestion

Avocado peel is a source of bioactive compounds with antioxidant, anti-inflammatory, antiproliferative and antimicrobial capacities, among others. Physical and chemical interactions of phenolic compounds with indigestible polysaccharides could affect their bioaccessibility in the upper gastrointestinal tract, allowing them to reach the colon, where they exert antioxidant effects and related health effects. The objective of the present work was to evaluate the effect of chemical-enzymatic processes of an in vitro gastrointestinal digestion, on phenolic compounds, antioxidant capacity and chemical constituents of avocado peel, and to determine their content in the indigestible fraction. Results showed that most phenolic compounds resist intestinal digestion (66%), of which 954.72 ± 19.45 mg GAE/100 g of dry weight (dw) and 250.72 ± 7.12 mg CE/100 g dw are hydrolysable and condensed tannins, respectively. The highest antioxidant capacity remained in the indigestible fraction (79.4%, 59.8% and 79.6%), with greater predominance in the insoluble indigestible fraction (49.1%, 46.6% and 66.7%) for DPPH, ABTS and FRAP, respectively. Most of the indigestible fraction is insoluble (89.39%), while only 7.46% is soluble. The possible beneficial effects of phenolic compounds and antioxidant capacity of the indigestible fraction of avocado peel must be considered in further studies.

BIOTECHNOLOGICAL ASPECTS OF BIOCONVERSION OF POST-EXTRACTION BIOMASS AND CELL CULTURE ORTHILIA SECUNDA (L.) HOUSE WITH BASIDIOMYCETES

The possibility of bioconversion after the extraction residue of the medicinal plant Orthilia secunda (initial plant biomass and callus after extraction of biologically active substances) by fast growing strains of basidiomycetes Tv2-16K Trametes versicolor and Pe-17T Pleurotus eryngii was studied. The main target products are: a mycelial-plant product with a reduced content of the indigestible fraction and enriched in protein and full-fledged fruit bodies. Fungi colonize plant waste with a radial growth rate of 2.0–2.3 mm / day and a growth rate of 65–77 units. Phenol oxidase activity is 0.7–1.2 units/g·s, depending on the type after the extraction residue. In substrates after biodegradation, the proportion of difficult hydrolysable polysaccharides, easily hydrolysable polysaccharides, and lignin is on average 1.6 times lower than in the original substrate. The content of protein and extractive substances is significantly higher, especially after the extraction residue of O. secunda callus under the influence of the T. versicolor strain Tv2-16K: 12.8 and 24.3%, respectively, of the mass of dry substrate. Fruit bodies of P. eryngii strain Pe-17T were obtained on various compositions of plant substrates. The maximum fruit formation was noted on four-component substrates containing two types after extraction residues of O. secunda, wheat bran, birch or aspen sawdust: the average weight of fruit bodies from one block was 230–236 g; biological efficiency – 46–47.2%.

Study of the impact of a dynamic in vitro model of the colon (TIM-2) in the phenolic composition of two Mexican sauces

Husk tomato (Physalis ixocarpa Brot. ex. Horm) is mainly used in the preparation of many Mexican sauces due to its unique and slightly acidic flavor, both in raw and cooked forms. These sauces also usually contain Serrano hot pepper (Capsicum annuum L), onion (Allium cepa L.), garlic (Allium sativum L.), coriander (Coriandrum sativum L.) and salt. Mexican sauces are a pre-Hispanic staple food, yet there is scarce knowledge on the phenolic compounds (PC) that reach the colon bound to the indigestible fraction (IF) after intestinal digestion. Thus, the aim of the present work was to evaluate the indigestible fraction of two types of Mexican sauces made with cooked and raw husk tomato: cooked green sauce (CGS) and raw green sauce (RGS). IF of CGS and RGS were fermented in the in vitro model of the human colon (TIM-2) to investigate the PC bioconversion by the gut microbiota after 24, 48 and 72 h. PC of the original sauces and their predigested fractions, as well as the formed metabolites were identified and monitored by HPLC-ESI-QToF-MS. Cooking husk tomato significantly increased the total indigestible fraction (TIF), mainly due to its insoluble indigestible fraction (IIF), and diminished PC. Flavonoids (flavonols and flavones) were the most abundant phenolic group in digested sauces followed by capsaicinoids (a characteristic group derived from hot pepper), hydroxycinnamic acids, and hydroxybenzoic acids. The metabolites 3-(ρ-hydroxyphenyl) propionic acid, 3-(3-hydroxyphenyl) propionic acid and 4-hydroxyphenylacetic acid were the most abundant colonic metabolites identified, which are thought to be derived from the biotransformation of flavonoids and hydroxycinnamates. These results are the first obtained on in vitro colonic fermentation of Mexican sauces and should be considered in future studies on the health effects related to consuming this staple food.

Determination of in situ degradation parameters and feeding level of pineapple (Ananas comosus L.) cannery by-product to Hanwoo steers.

ObjectiveThe objectives of this study were to determine the in situ degradation parameters and appropriate feeding level of pineapple cannery by-products (PCB) based on the growth performance and blood parameters of growing Hanwoo (Bos taurus coreanae) steers fed various levels of PCB.MethodsTwo ruminally cannulated Holstein cows were used for in situ disappearance rate measurements. Nylon bags (5×10 cm, 45 μm pore size) filled with 5 g of PCB in triplicate were inserted into the ventral sac of the two cannulated Holsteins cows and incubated for 0, 2, 4, 8, 16, 24, and 48 h. A total of 16 castrated growing Hanwoo steers (12.5±0.5 months old, 302.9±25.7 kg of initial body weight [BW]) were used for the experiment. Animals were stratified by initial BW and then randomly assigned to one of four experimental diets (0%, 1.5%, 3.0%, or 6.0% of PCB, on the dry matter [DM] basis) fed for 91-d, including 30-d of adaptation.ResultsSoluble fraction a of DM and crude protein (CP) was 61.9% and 86.0%, fraction b of DM and CP was 32.7% and 11.2%, and indigestible fraction c of DM and CP was 5.4% and 2.8%. The 6.0% PCB feeding group showed lower productivity compared to animals in the other treatments. Increasing the dietary level of PCB did not alter DM intake, but it was numerically lowest in the 6.0% feeding group. The gain to feed ratio was linearly decreased by increasing of PCB. The quadratic broken-line test estimated that 2.5% (DM basis) was the maximum feeding level of PCB in growing Hanwoo steers (y = 0.103 − 0.001×[1.245−x]2, R2 = 0.18).ConclusionDiets containing up to 2.5% PCB can be fed to growing Hanwoo steers without adverse effects on growth performance.

Efeitos da inclusão de taninos em suplementos de bovinos de corte em pastejo sobre a degradabilidade in situ da matéria seca

Objetivou-se com o presente estudo avaliar o efeito da inclusão de tanino na suplementação de bovinos a pasto sobre a degradabilidade da matéria seca. Foram utilizados dois bovinos machos Nelore, não castrado, canulados no rúmen, e suplementados com suplemento proteico-energético com 26% de proteína bruta (PB) a 0,5% do peso corporal, contendo na dieta de um dos animais a inclusão de 1g de tanino por kg de matéria seca (MS). Avaliou-se a degradação da MS das amostras de DDG (que significa grãos secos por destilação, na sigla em inglês), farelo de soja e milho. Para todos os alimentos não houve diferença significativa entre os tratamentos. O DDG apresentou fração indigestível (65,6%) maior que a fração potencialmente digestível (20,5%), a fração potencialmente degradável da MS (B0) do farelo de soja foi inferior ao observado na literatura, entretanto a taxa de degradação da fração B0 (0,037) foi semelhante (0,080). O melhor ajuste dos modelos de desaparecimento para MS do milho foi com os tratamentos separados. Porém, não houve diferença significativa entre eles. A taxa de degradação do tratamento com tanino (0,178) não apresenta confiabilidade por incluir o zero dentro do intervalo de confiança. Existe uma diferença significativa somente no tempo de meia vida, sendo possível observar que o tratamento com tanino demora quase que o dobro de tempo (96,35%) para digerir metade da fração potencialmente digestível do tratamento sem tanino.

By-Product of Cotton Agribusiness as an Alternative Protein Source for Rams

The aim of this study was to evaluate the effect on intake, digestibility and fractionation of carbohydrates and proteins of cottonseed cake as an alternative protein source in rams diets. The diets were composed of corn silage, soybean meal, ground corn, urea, and cottonseed cake (0, 70, 140 and 210 g/kg dry matter (DM)) in a roughage/concentrate ratio of 50:50. Thirty-two Santa Ines rams, average age 12 months and weight 27.48 ± 4.96 kg were distributed in a completely randomised design. A reduction of 0.161 g/day in crude protein (CP) intake was observed for each gram of cottonseed cake inclusion. The intake of non-fiber carbohydrate (NFC) decreased by 0.511 g/day for each gram of cottonseed cake inclusion. Similarly, the ratio between intake of DM (p = 0.034), CP (p < 0.001), NFC (p = 0.004) and body weight decreased with cottonseed cake inclusion. Inclusion of cottonseed cake caused decreases in the digestibility coefficients of DM (p < 0.001), CP (p < 0.001) and NFC (p = 0.002). A reduction of 0.716 g was observed in carbohydrate fraction A + B1 (p = 0.006). The inclusion of cottonseed cake in the rams feed should be carried out with caution because this by-product promotes linear reduction in intake and digestibility nutrient, in addition to modifying the amounts of digestible and indigestible fractions in the diets.

Characterisation and In Vitro Evaluation of Fenugreek (Trigonella foenum-graecum) Seed Gum as a Potential Prebiotic in Growing Rabbit Nutrition.

Simple SummaryA fenugreek seed gum, extracted from Trigonella foenum-graecum seeds and rich in galactomannan, was chemically and physically characterised and its prebiotic potential for young rabbits was evaluated in vitro, both as pure fenugreek seed gum and when included up to 20 g/kg in rabbit diets rich in soluble and insoluble fibre. Fenugreek seed gum was resistant to pepsin and pancreatin digestion but was totally fermented by rabbit caecal bacteria. Fenugreek seed gum linear inclusion up to 20 g/kg in diets rich in soluble fibre has led to a reduction in the solubility of some nutrients during in vitro enzymatic phase and an increase in the fermented fraction. Fenugreek seed gum satisfies two essential conditions of a prebiotic: resistance to enzymatic digestion and being totally fermented by caecal bacteria.Some components of soluble fibre appear to have prebiotic effects that can contribute to improving digestive health in post-weaning rabbits. In this work, a fenugreek seed gum (FGS), extracted from Trigonella foenum-graecum seeds and rich in galactomannan, was characterised. Both the pure FSG and ten substrates obtained by the inclusion of 0, 5, 10, 15 and 20 g/kg of FSG in diets rich in soluble (SF) and insoluble (IF) fibre were evaluated in vitro to determine FSG prebiotic potential for rabbit diets. FSG was rich in total sugars (630 g/kg dry matter), consisting entirely of galactose and mannose in a 1:1 ratio, and a moderate protein content (223 g/kg dry matter). Pure FSG was affected very little by in vitro digestion, as only 145 g/kg of the FSG was dissolved during the enzymatic phase. However, the linear inclusion of FSG up to 20 g/kg in growing rabbit feeds has led to a reduction in the solubility of some nutrients during in vitro enzymatic phase, especially in SF diets. Pure FSG not digested during the enzymatic phase almost completely disappeared during the in vitro fermentation phase, 984 g/kg of this indigestible fraction. However, although linear inclusion of FSG up to 20 g/kg in SF diets increased the fermented fraction, no relevant changes in the fermentation profile were observed. In conclusion, FSG satisfies two essential conditions of the prebiotic effect, showing resistance to in vitro enzymatic digestion and being totally fermented in vitro by caecal bacteria, although in vivo studies will be necessary to determine its prebiotic potential.

Improvement of Benin Patties and The Effects of Added Some Flour on Physicochemical Properties

The residue of peanut oil extraction in Benin entered manufacture of snack locally called kluiklui. This snack was obtained after deep frying defatted dough of crushed seeds. This paper dealt with exploration and determination of patties physichochemical characteristics linked to crunchy descriptors and induced effects of adding some flour such as banana flour and glucomannan to defatted groundnut cake. Obtained results showed that, incorporating flour at reasonable percentages 5 % (mass basis) improve crunchy quality and increase the indigestible fractions. However, recorded high value of remanant moisture 6.39 to 9.3% (dry basis) and fat 26.42 to 31.95% (dry basis), in the fried snack required further drying and improved oil cooking. The addition of flour increased the indigestible fraction in the kluiklui. Sample made with de-oiled peanut paste, glucomannan and type 3 resistant starch banana flour exhibited the highest indigestible fraction values attributed to the synergistic presence of the resistant starch, dietary fiber, protein and non-starch polysaccharides. The same sample exhibited lower fracturability and higher hardness than others. Results of the sensory quality evaluation showed that incorporation of flour into the kluiklui showed no significant differences in liking scores in terms of appearance, aroma, taste and overall acceptability; whereas, the texture and the color scores were significantly different than the control kluiklui. Although the use of flour does not arouse consumer’s acceptability. Flour-enriched kluiklui was significantly higher in all the sensory attributes considered. Overall, the flour-enriched kluiklui produced, was favorably and acceptable, thus showing prospects for industrial application of the flour-enriched kluiklui. In addition, the low resistance to rupture of flour-enriched kluiklui has confirmed their crispy behavior compared to those resulting from defatted pure cake. The resistance of the texture indicated that the production conditions were unfavorable for handling and transport and Overall, banana flour and glucomannan can be successfully incorporated into kluiklui to enrich its values contents.

Stability and anti-topoisomerase activity of phenolic compounds of Capsicum annuum “Serrano” after gastrointestinal digestion and in vitro colonic fermentation

“Serrano” pepper is extensively used in Mexican cuisine. The aim of this study was to identify the bioaccessible phenolic compounds (PC) of “Serrano” pepper as well as short-chain fatty acids (SCFA) produced and PC bioconverted using an in vitro step-wise gastromimetic model of the intestinal digestion and anaerobic fermentation of the isolated indigestible fraction (IF). The anti-topoisomerase activity of the fermented samples was also evaluated. PC bioaccessibility was about 45% in the small intestine. Chlorogenic acid and capsaicin were identified during the intestinal digestion, while quercetin was identified as available to the gut microbiota. After 48-h fermentation, SCFA molar ratio was 77:11:12 for acetic, propionic and butyric acid. The PC identified in IF and after 12 h of fermentation showed anti-topoisomerase activity. A synergistic effect among the PC and gut metabolites mixture was observed, which indicates a possible antiproliferative mechanism that should be tested in further studies.

Changes in Intestinal Microbiota and Predicted Metabolic Pathways During Colonic Fermentation of Mango (Mangifera indica L.)-Based Bar Indigestible Fraction.

Mango (Mangifera indica L.) peel and pulp are a source of dietary fiber (DF) and phenolic compounds (PCs) that constituent part of the indigestible fraction (IF). This fraction reaches the colon and acts as a carbon and energy source for intestinal microbiota. The effect of mango IF on intestinal microbiota during colonic fermentation is unknown. In this study, the isolated IF of a novel ‘Ataulfo’ mango-based bar (snack) UV-C irradiated and non-irradiated (UVMangoB and MangoB) were fermented. Colonic fermentation occurred in vitro under chemical-enzymatic, semi-anaerobic, batch culture and controlled pH colonic conditions. Changes in the structure of fecal microbiota were analyzed by 16s rRNA gene Illumina MiSeq sequencing. The community´s functional capabilities were determined in silico. The MangoB and UVMangoB increased the presence of Faecalibacterium, Roseburia, Eubacterium, Fusicatenibacter, Holdemanella, Catenibacterium, Phascolarctobacterium, Buttiauxella, Bifidobacterium, Collinsella, Prevotella and Bacteroides genera. The alpha indexes showed a decrease in microbial diversity after 6 h of colonic fermentation. The coordinates analysis indicated any differences between irradiated and non-irradiated bar. The metabolic prediction demonstrated that MangoB and UVMangoB increase the microbiota carbohydrate metabolism pathway. This study suggests that IF of mango-based bar induced beneficial changes on microbial ecology and metabolic pathway that could be promissory to prevention or treatment of metabolic dysbiosis. However, in vivo interventions are necessary to confirm the interactions between microbiota modulating and intestinal beneficial effects.

Bromatological quality of silage from cassava residues: fractionation of proteins and carbohydrates

ABSTRACT The objective of this study was to evaluate the quality of silage in the upper third of cassava levels of inclusion of cassava peel, 0, 100, 200, 300, 400 g/kg out based on natural matter (NM) with 60 days of storage on fermentative profile, aerobic stability, chemical composition and protein and carbohydrate fractionation. The material was ensiled in 15 experimental silos, the experimental design adopted was completely randomised, with five treatments and three repetitions. The inclusion of cassava peel in silage from the aerial part of the cassava promoted an increasing linear effect for dry matter content. The contents of crude protein, neutral detergent fibre and acid detergent fibre decreased linearly (P < 0.05) with the inclusion of cassava peel in the silage. The inclusion of the bark promoted an increase in carbohydrate levels. Protein and carbohydrate fractions were influenced by the addition of cassava peel, decreasing the unavailable and/or indigestible fraction (Fraction C) of proteins and carbohydrates. The inclusion of cassava peel up to the level of 400 g/kg NM in silage from the aerial part of the cassava improves the fermentation process, aerobic stability and the chemical composition of the silage, and reduces the indigestible fractions of carbohydrates and proteins.

Effects of ensiling time on corn silage neutral detergent fiber degradability and relationship between laboratory fiber analyses and in vivo digestibility

Accurate analysis of degradability of silage neutral detergent fiber (NDF) is important for diet formulation and to predict lactational performance of dairy cows. In this study, 5 corn silage hybrids ensiled for 0 (unfermented), 30, 60, 120, and 150 d were used to determine the effects of ensiling time on silage neutral detergent fiber degradability (NDFD) and to assess the relationships between near-infrared reflectance spectroscopy (NIR) NDF-related analyses and in situ NDFD variables. In addition, the relationships between dietary concentration of indigestible NDF, 288-h incubation (iNDF288), or undegraded NDF, 240-h incubation (uNDF240), and in vivo total-tract apparent organic matter and NDF digestibility were studied in total mixed ration samples from 16 experiments with lactating dairy cows. Ensiling time had no effect on silage NDF concentration; however, the ratio of acid detergent fiber ÷ NDF increased, and estimated hemicellulose concentration decreased quadratically with ensiling time. Also, concentration of NDF-bound protein decreased, and that of lignin increased linearly with ensiling time. These changes in silage fiber composition resulted in a linear decrease in in situ effective degradability of silage NDF with increasing ensiling time. The indigestible fraction of NDF and concentration of structural carbohydrates were not affected by ensiling time. Correlations of in situ NDFD variables with laboratory NIR NDFD analyses were weak to moderate. The relationship of corn silage uNDF240 with lignin concentration or 30-h NDFD (all NIR analyses) was remarkably good (R2 = 0.73 and 0.88, respectively). The relationship between in situ iNDF288 concentration (but not uNDF240) and in vivo total-tract apparent digestibility of dietary organic matter and NDF was good (R2 = 0.72 and 0.80, respectively). In conclusion, in situ degradability of silage NDF linearly decreased from 0 to 150 d ensiling time, primarily caused by a decrease in concentrations of hemicellulose and NDF-bound protein. In situ NDF degradability measurements and common laboratory NIR NDF-related analyses were generally poorly correlated. We found a good relationship between in vivo NDF digestibility and dietary concentration of iNDF288 determined in situ, but the relationship with uNDF240 was poor.

Optimized germinated soybean/cornstarch extrudate and its in vitro fermentation with human inoculum.

The aim of this work was to optimise a soybean/cornstarch extrudate by adjusting a central composite design and to maximise a product with a high protein and resistant starch (RS) content by evaluating the indigestible fractions through in vitro colonic fermentation and production of short-chain fatty acids (SCFAs) with potential health benefits. According to the response surface analysis and RS maximisation results, an optimisation of the independent variables was obtained as follows: 32.5% feed moisture, 144°C extrusion temperature and a proportion of 44% germinated soybean flour and 56% cornstarch. A product with a 2.11% expansion index, 6.25N hardness, a glycaemic index of 49 and 12% resistant starch was obtained. The optimised extrudate showed a 36% indigestible fraction and high fermentability with respect to that of the lactulose control. Furthermore, the decrease in pH was inversely proportional to the production of SCFAs and the volume of gas generated. Acetic, propionic, and butyric acids were produced at a molar ratio of 62:27:11, while the highest SCFA concentrations were found 48h after incubation. The RS of the optimised extruder was a viable substrate for in vitro colonic fermentation, suggesting that it is a good food source to produce SCFAs, which could exert an effect on the regulation of lipid and glucose metabolism.

Partial swelling of granules enables high conversion of normal maize starch to glucose catalyzed by granular starch hydrolyzing enzyme

Maize starch is an abundant renewable biopolymer that can be processed into sugars and ethanol, or other fermented chemicals. The objectives of this study were to examine how partial swelling of starch granules enhanced the starch saccharification process, characterize the indigestible residues, and determine the optimal conditions for glucose production. Normal maize starch (2.0% in 50 mM citrate butter) was partially swollen by heating at 62, 65, and 70 °C for 30 min, and the preswollen starch hydrolyzed by addition of a granular starch hydrolyzing enzyme (GSHE). After preswelling at 70 °C, enzyme kinetics study of the release of glucose showed a 54% reduction in the Michaelis-Menten constant (Km), suggesting that preswelling increased the complexing of GSHE with the starch granules. Preswelling the starch at 62, 65, and 70 °C followed by digestion with 1.0% GSHE (starch basis) at 62 °C for 24 h in 50 mM citrate buffer (pH 4.5) resulted in 61.3, 76.0, and 94.5% conversion to glucose. The indigestible fraction, compared to the untreated starch, had a lower A-type crystallinity and probably less amylose-lipid complex, was more highly branched, contained a higher proportion of short chains, and showed a higher gelatinization temperature but lower enthalpy of gelatinization. The indigestible fraction, after preswelling at 100 °C in citrate buffer, was converted practically quantitatively to glucose. Partial swelling of granules offers great potentials in converting starches to sugars by GSHE.

Esterified plantain flour for the production of cookies rich in indigestible carbohydrates

The role of raw plantain flour (RPF) and its citric acid (CA)-esterified counterpart (EPF) on the carbohydrate nutritional properties of cookies was investigated. Cookies were elaborated with commercial wheat flour (CWF), RPF, EPF, or a CWF-EPF blend, and assessed for composition, starch digestibility, texture and sensory properties. EPF-cookie showed the lowest digestible starch (DS) content and estimated glycemic index (pGI) (25.0% and 59.3, respectively). Cookies made with CWF-EPF exhibited the highest indigestible fraction values attributed to the synergistic presence of the RS from EPF and the protein and non-starch polysaccharides from CWF. All RPF containing cookies exhibited lower hardness than CWF-cookie. Although the use of RPF decreased consumer’s acceptability compared to CWF-cookie, the cookies with EPF showed sensory characteristics of 52–65% compared with the CWF-cookie (100%). This study shows CA esterification of plantain flour as a successful strategy to manufacture cookies with low DS and pGI.

Short communication: Effect of washing method, grinding size, and the determination of an indigestible fraction on in situ degradation of starch in mature corn grain

The objectives of this study were to determine (1) the effect of grinding size (1, 2, 4, and 6 mm) to determine effective ruminal disappearance (ERD); (2) the most adequate method to estimate the rapidly degradable fraction (A); (3) a time point to measure the indigestible fraction (C); and (4) the viability of using fewer time points to estimate starch fractional disappearance rate (kd) of mature corn grain. Fraction A was determined by rinsing in a bucket or washing machine, rumen immersion followed by bucket or washing machine, and water immersion for 30 min followed by bucket or washing machine. Ruminal in situ incubations were performed at 48, 72, 96, and 120 h to determine fraction C, and at 0 (washing machine), 3, 6, 12, 18, 24, and 48 h to determine the kinetics of starch disappearance. Models were used with either 2 or 3 pools and kd was determined by the linear slope of the log-transformed bag residues as a proportion of incubated samples over time. The ERD was calculated as A + B [kd/(kd + kp)], where kp is the ruminal fractional passage rate = 16.0% h-1. Data were analyzed using PROC MIXED of SAS (SAS Institute Inc., Cary, NC) with the fixed effects of run (for fraction A analysis only) method (either washing or model), grinding size, and method by grinding size interaction, with cow as a random effect. Correlation between estimates calculated using all time points or combinations of 2 and 3 time points were determined using PROC CORR. Fraction A was reduced as grinding size increased, but was not altered by washing method. Samples ground at 6 mm had greater fraction C than other grinding sizes at 48, 72, or 96 h, but not at 120 h. Model affected the slowly degradable fraction (B) values solely, but the difference was minor (0.5 percentage units). Greater fractions B and C but reduced kd and ERD were observed as grinding size increased. Based on correlation analysis the 2-pool model, incubation times of 0, 3, and 48 h were suitable to evaluate ruminal starch degradation kinetics in mature corn. Ruminal in situ incubation at 120 h highlighted the lack of a fraction C of starch (0.13% of starch). Washing method did not affect determination of fraction A of starch. Ruminal in situ incubations of 0, 3, and 48 h for starch degradation kinetics using a 2-pool model were adequate for mature ground corn, but 120 h of incubation is suggested to confirm the existence or absence of a fraction C. Grinding size affected starch degradation kinetics and fraction A determination.

Efecto de la extracción asistida por ultrasonido en la liberación y bioaccesibilidad in vitro de carotenoides, en bebidas elaboradas con mango (Mangifera indica L.) ‘Ataulfo’

Introducción: Durante el proceso de industrialización del mango se generan cerca del 40 % de subproductos (SP, cáscara y pasta). Estos SP contienen carotenoides que benefician a la salud del consumidor. Por lo tanto, es un tema de interés conocer si los carotenoides pueden ser bioaccesibles. De tal manera, la extracción asistida por ultrasonido (EAU) ha demostrado ser una herramienta útil para aumentar la bioaccesibilidad de diversos compuestos bioactivos. Se propone elaborar bebidas con SP de mango ‘Ataulfo’ aplicando la EAU y evaluando la bioaccesibilidad de los carotenoides in vitro.Método: Se elaboraron 4 bebidas: una control (BC) y tres utilizando la EAU (B-EAU1: XTE: 30 min, XAS: 30 %, XC: 0.8; B-EAU2: XTE: 15 min, XAS: 70 %, XC: 0.4; B-EAU3: XTE: 12 min, XAS: 100 % y XC: 1). Se determinó el perfil de los carotenoides por HPLC-DAD y la bioaccesibilidad in vitro de los carotenoides. Se evaluó la liberación de los compuestos en la digestión gástrica (DG) e intestinal (DI); así como la retención de éstos en la fracción indigestible soluble (FIS) e insoluble (FII). De esta manera, se determinó el porcentaje de bioaccesibilidad (%BA) de los carotenoides. Se determinó la cinética de liberación durante 180 min,estimando los parámetros cinéticos.Resultados: El contenido de los carotenoides osciló entre 0.01 a 3.29 µg/100 mL en las bebidas de mango. Las xantofilas mostraron diferencia significativa en todas las bebidas con EAU en la DI. La EAU tuvo un efecto negativo sobre el contenido de β-criptoxantina, luteína, y β-caroteno en B-EAU2 y B-EAU3. Por otra parte, el contenido de α-caroteno fue similar en todas las bebidas. En la DI, el contenido de α-caroteno y β-caroteno fueron altos en la BC y los contenidos de luteína y zeaxantina fueron mayores en B-EAU1. El %BA de luteína, zeaxantina, α-caroteno y β-caroteno en la B-EAU1 fue del 95.63, 56.88, 58.68 y 90.54 %, respectivamente. Sin embargo, la β-criptoxantina y zeaxantina fueron los menos bioaccesibles en BC y B-EAU3 con 96.5 y Zea 92.3 %, respectivamente. La B-EAU1 presentó una mayor velocidad de liberación de luteína, β-criptoxantina y β-caroteno.Discusión o Conclusión: La EAU ocasionó una disminución en el contenido de los carotenoides, debido probablemente a reacciones de isomerización. La liberación de xantófilas y carotenos en las bebidas de mango, pudo deberse a factores asociados a los componentes de la matriz del alimento, interacciones de los carotenoides con otros componentes y el tratamiento al que se sometieron las bebidas. Por otro lado, la EAU favoreció la liberación de estos compuestos. La presencia de carotenoides en la FIS y FII se puede atribuir a la fibra dietética de la cáscara y la goma xantan adicionada. La EAU contribuyó al aumento del %BA de los carotenos y xantofilas. También, los parámetros de las cinéticas de liberación mostraron que el EAU facilitó el transporte de los carotenoides. Por lo tanto, los parámetros de la cinetica de liberación muestran que existen factores que influyen este fenómeno como la acción sinérgica o antagónica entre los carotenoides y otros componentes.