Starch Digestibility (starch + digestibility)

Distribution by Scientific Domains

Selected Abstracts

The effects of urea-treated potato pulp (PP) ensiled with beet pulp or wheat bran pellets to reduce moisture of PP and flake density of corn grain supplemented with the PP silage on digestibility and ruminal fermentation in beef steers

ABSTRACT The effects of adding beet pulp or wheat bran to urea-treated potato pulp (PP) in order to reduce moisture of PP silage and flake density of corn grain on digestibility and ruminal fermentation in beef steers were studied in a split-plot design experiment. The whole-plot treatments were PP silage mixed with 0% added pellets (CON), 9% (as-fed basis) beet pulp pellets (BP) or 9% (as-fed basis) wheat bran pellets (WB) as water-absorbing materials. The subplot treatments consisted of supplements formulated to contain either high-density corn (HDC) or low-density corn (LDC). BP steers consumed more (BP vs WB, P = 0.011) concentrate than did WB steers, whereas hay intake did not differ between the treatments. Dry matter (BP vs WB, P = 0.023) and organic matter (BP vs WB, P = 0.029) digestibility were higher for BP steers than for WB steers. Starch digestibility was higher (P = 0.006) for LDC than for HDC. There were no differences in the concentration of ruminal ammonia nitrogen among the treatments. Molar proportions of ruminal acetate were higher for BP steers than for WB steers (BP vs WB, P = 0.030). Conversely, molar proportions of propionate were lower for BP steers than for WB steers (BP vs WB, P = 0.044). Flake density of corn did not affect ruminal characteristics. In conclusion, from the viewpoint of feed intake and digestibility, BP is superior to WB as a moisture control material for urea-treated PP silage, and flake density of corn supplemented with urea-treated PP silage does not alter ruminal fermentation. [source]

Changes in the biochemical and functional properties of the extruded hard-to-cook cowpea (Vigna unguiculata L. Walp)

Karla A. Batista
Summary Changes in the biochemical and functional properties of the hard-to-cook cowpea bean after treatment by the extrusion process are reported. The extrusion was carried out at 150 °C, with a compression ratio screw of 3:1, a 5-mm die, and a screw speed of 150 r.p.m. The extrusion caused the complete inactivation of the ,-amylase and lectin and it also reduced the trypsin inhibitor activity (38.2%) and phytic acid content (33.2%). The functional properties were also modified by the process, an increase of 2.5 times in the water absorption index and 3.1% in the water solubility were observed. The digestibility of the hard-to-cook flour of the cowpea bean was improved after the extrusion, with a 55.9% increase in protein digestibility and a 5.9% increase in starch digestibility. [source]

Effect of fermentation on in vitro digestibilities and the level of antinutrients in moth bean [Vigna aconitifolia (Jacq.) Marechal]

Amrit Bhandal
Summary The effect of fermentation with varying temperatures and time periods on the nutritive value of Moth bean was studied. Results indicated that at 30 °C, protein digestibility increased from 60% in the non-processed moth bean to 77%, 78% and 80% and at 35 °C, increased to 81%, 83% and 85% following 12, 18 and 24 h of fermentation (controlled) period, respectively. Fermentation also caused an appreciable enhancement (96,133%) in starch digestibility with increase in period and temperature of fermentation. Fermentation of moth bean resulted in 24,34% reduction in phytic acid content at 30 °C and 33,42.5% at 35 °C. Polyphenol content was reduced by 42%, 48% and 51% at 30 °C and by 44%, 49% and 54% at 35 °C after 12, 18 and 24 h of fermentation period, respectively. Prolonging the period of fermentation from 12 to 18 and 24 h at 30 °C also caused a loss in TIA. [source]

The effects of hydrothermal processing on antinutrients, protein and starch digestibility of food legumes

Zia -ur-Rehman
Summary The effects of hydrothermal processing on antinutrients and the protein and starch digestibility of black grams, chick peas, lentils and red and white kidney beans was investigated. The tannins and phytic acid contents in these five food legumes ranged from 770 to 1100 and 970 to 1440 mg/100 g, respectively, whereas protein and starch digestibility of the raw food legumes was found to be from 33.8 to 37.6 and 36.8 to 42.0%, respectively. A reduction in the level of these antinutrients, along with an improvement in protein and starch digestibility, was observed after cooking. The tannins and phytic acid contents were reduced by 33.1,45.7 and 28.0,51.6%, respectively, because of the use of different hydrothermal treatments at 100, 121 and 128 °C. Maximum improvement in protein digestibility (95.7,105.1%) and starch digestibility (116.7,137.7%) was observed on cooking at 121 °C for 10 min. However, cooking in boiling water resulted in improvement in protein and starch digestibility of the food legumes by 86.9,93.3 and 84.0,90.4%, respectively. [source]

Proximal composition and in vitro starch digestibility in flaxseed-added corn tortilla

Rodolfo Rendón-Villalobos
Abstract BACKGROUND: The effect of addition of flaxseed flour (10:90, 15:85 and 20:80, w/w) on the chemical composition and starch digestibility of corn tortilla was investigated. Tortillas were baked and frozen in liquid nitrogen, freeze-dried, ground and analyzed for fat, protein, ash, total starch (TS), available starch (AS) and resistant starch (RS) contents as well as for starch hydrolysis rate and predicted glycemic index (pGI). Tortillas made from commercial nixtamalized corn flour were used as control sample. RESULTS: Flaxseed flour addition increased the fat and protein content of tortilla, whereas TS and AS decreased. TS was 15.25% lower in the 20% flaxseed-containing tortilla as compared to the control sample. The AS content was 12.65% lower in the composite tortilla. RS content in the samples ranged between 1.92% for the control sample and 5.08% for the tortilla containing 20% flaxseed. The reduced enzymatic starch hydrolysis rate and pGI recorded for the flaxseed-added tortilla, indicated slow digestion features. CONCLUSIONS: Flaxseed-added tortilla might be used to increase the consumption of ,-linolenic acid in the daily diet and modulate starch digestibility of corn tortilla. This kind of product may be used by people with special diet reqirements. Copyright © 2008 Society of Chemical Industry [source]

Comparison of in vitro starch digestibility methods for predicting the glycaemic index of grain foods

Kirsty A Germaine
Abstract BACKGROUND:In vitro starch digestibility tests are useful for the prediction of glycaemic index (GI). However, there are no internationally recognised methods and no one method has been found to be suitable for all food types. This study compared six in vitro methods, using four grain foods, including those with a varied particle size and soluble fibre content. Method variations included using chewing or mincing, mincing with or without amylase and incubation in a restricted versus non-restricted system. Hydrolysis index (HI) values, calculated from the starch digestibility curves and GI prediction equations were used to compare the in vitro results to GI. RESULTS: HI values for five of the six methods ranked all foods in the same order as the GI values. Using a GI prediction equation (predicted GIHI) the mincing (without amylase) non-restricted method had the smallest standard error of prediction between the predicted GIHI and GI values. This method was then validated using 14 grain foods and demonstrated a significant correlation (r = 0.93, P < 0.01) between the in vitro starch digestibility and reported GI responses. CONCLUSIONS: The non-restricted mincing method showed good potential as a new in vitro starch digestibility method for predicting GI in grain foods. Copyright © 2007 Society of Chemical Industry [source]

Chemical composition and in vitro starch digestibility of pigmented corn tortilla

Juan Pablo Hernández-Uribe
Abstract BACKGROUND: Tortillas were prepared from two (blue and regular white) maize varieties and compared with regard to chemical composition and in vitro starch digestibility, i.e., available starch (AS), total (RS) and retrograde (RRS) resistant starch contents, amylolysis rate and predicted glycemic index (pGI). The impact of cold storage (4 °C) on digestibility was also investigated. RESULTS: Despite its higher protein and lipid contents, pigmented tortilla exhibited lower AS content than the white product. AS in both types of tortilla decreased during the first 2 days of storage, and remained stable thereafter. Blue tortilla had lower RS content (21 g kg,1 dry matter basis) than the white tortilla (30 g kg,1 dry matter basis). RS values were slightly higher in 2 day-stored tortillas than in their fresh counterparts. Although the RRS content in recently made white tortillas was greater than in the colored preparation, stored blue tortillas exhibited double RRS values compared with freshly baked samples. ,-Amylolysis of blue tortilla was slower than in the white sample. Consequently, blue tortilla exhibited a lower pGI value. pGI for the white tortilla decreased upon cold storage, a change that was not be observed for the colored preparation. CONCLUSION: Starch digestibility characteristics of blue tortilla make it suitable for people with special nutritional or metabolic requirements. Copyright © 2007 Society of Chemical Industry [source]

Long-term effects on the digestive tract of feeding large amounts of resistant starch: A study in pigs

Daniel Martínez-Puig
Abstract The present study aimed to assess the digestive consequences of the long-term intake of two starches providing different amounts of resistant starch. Growing pigs were used as the animal model and meal-fed for 14 weeks on a diet containing a high amount of either raw potato starch (RPS) or corn starch (CS). Digestive adaptation was chronologically evaluated by measuring organic matter (OM), crude protein (CP), neutral detergent fibre (NDF) and starch digestibility. After 97 days, whole-tract digestibility of OM, CP and NDF was lower for RPS- compared to CS-fed pigs, whereas no differences were observed in faecal starch digestibility. In contrast, starch digestibility was reduced in the proximal compartments (ileum, caecum and proximal colon) of animals fed the RPS diet. The concentration of short-chain fatty acids (SCFAs; P < 0.05), and purine bases (PBs; P < 0.01) was also higher in distal colon and rectum of animals fed the RPS diet. Changes in bacterial community structure (dendogram analyses) were seen in the rectum. Biodiversity tends to increase more in RPS compared to CS fed animals (34.1 vs. 28.8; P = 0.07). Among SCFAs, the proportion of butyrate was two-fold higher in proximal colon digesta of RPS compared to CS fed pigs (0.20 vs. 0.11; P < 0.05). Increased butyrate formation in the colon reduced the number of apoptosis per crypt in the proximal colonic mucosa (0.38 vs. 0.62; P < 0.05). RPS fermentation reduced indices associated with damage to intestinal epithelial cells, such as crypt cell hyperproliferation and magnesium excretion. Long-term ingestion of RPS induces pronounced changes of the digestive tract and their microflora, modifying mineral absorption and colonic morphology for which health benefits are likely to be associated. Copyright © 2007 Society of Chemical Industry [source]

In vitro starch digestibility of fresh and sun-dried faba beans (Vicia faba L.)

Luis A Bello-Pérez
Abstract Fresh and sun-dried faba beans (Vicia faba L.) were cooked, stored for various times at 4 °C and analysed for available starch (AS), resistant starch (RS) and fibre-associated resistant starch (FARS) contents as well as ,-amylolysis. Fresh beans required a shorter cooking time (25 min) than dried beans (158 min). Cooked fresh faba beans had a higher AS content than cooked dried faba beans. The AS content in both decreased during cold storage, with fresh beans showing a smaller decrease than dried beans with increasing storage time. Cooked fresh faba beans also had a higher total RS content than cooked dried faba beans, although a greater increase in RS content was recorded in the latter upon storage. Starch retrogradation was more prominent in cooked dried faba beans than in cooked fresh faba beans, as indicated by the consistently higher FARS content. The ,-amylolysis rate decreased with increasing storage time, i.e. long-stored (72 h) cooked faba beans exhibited slower starch digestion, and differences were recorded between fresh and dried beans. The predicted glycaemic index ranged between 60.9 and 58.0% for cooked fresh faba beans and between 57.9 and 55.8% for cooked dried faba beans, which is suggestive of slow glucose release from starch in faba beans. Copyright © 2007 Society of Chemical Industry [source]

Effect of processing and storage time on in vitro digestibility and resistant starch content of two bean (Phaseolus vulgaris L) varieties

Perla Osorio-Díaz
Abstract Seeds from two commercial bean varieties were cooked and stored for different times and analysed for chemical composition and in vitro starch digestibility. Parallel portions of cooked seeds were dried at 55 °C, milled and stored as flours. In general, protein and ash contents in both samples did not change with storage time, but statistical differences were shown between the two varieties (p < 0.05). Available starch (AS) contents in flours from the ,negro' variety did not change (p < 0.05) with storage time and, in general, were higher than in ,flor de mayo' samples, whose AS levels decreased during storage. The lower AS in ,flor de mayo' flour could be the consequence of formation of resistant starch due to retrogradation. Samples of whole ,negro' seeds did not show differences in AS content at 0, 24 and 48 h of storage compared with the corresponding flours, but at 72 and 96 h the AS increased in the whole samples. ,Flor de mayo' showed a similar pattern in flour and whole samples, with slightly higher values in the whole seeds. In general, total resistant starch (RS) content in the two varieties was higher in the flours than in ,whole' seeds, a fact that is not easy to explain at present. ,Negro' flour presented an RS content around 65.0 g kg,1, and approximately 55.0 g kg,1 was recorded in ,flor de mayo', with slight changes when storage time increased. Whole ,flor de mayo' showed significant levels of the retrograded portion of resistant starch (RRS), which did not change with storage time (p < 0.05). However, values were lower than in the flours. A pattern similar to that of the ,negro' variety was obtained for ,flor de mayo', since the flour exhibited higher amounts of RRS; however, in this variety, the RRS content in ,whole' samples decreased after prolonged storage. Flours presented higher amylolysis rates than whole samples, and the ease of digestion increased with storage time. Copyright © 2003 Society of Chemical Industry [source]

Transgenic wheat: where do we stand after the first 12 years?

H.D. Shewry Jones
Abstract Wheat was among the last of the major crops to be transformed (in 1992), and transformation is still difficult, with a lower efficiency than that for maize and rice. However, the recent development of Agrobacterium -based systems is set to improve the precision of the process, while new methods of selection, removal of unnecessary DNA sequences, gene targeting and in vivo mutagenesis will make the process cleaner and more acceptable to regulatory authorities and consumers. Our current work is focussed on using transformation to understand and manipulate aspects of grain processing quality, notably dough strength and texture for milling. However, it is clear that a major priority for future work will be to improve nutritional quality, including vitamin and mineral contents for the developing world and starch digestibility and dietary fibre content and composition for developed countries. [source]

Digestibility and growth performance of juvenile rainbow trout (Oncorhynchus mykiss) fed with pea and canola products

D.L. Thiessen
A digestibility experiment and subsequent 84-day feeding experiment evaluated the use of pea and canola meal products in diets for rainbow trout. The effect of milling and heat treatment on nutrient, dry matter and energy digestibility of raw/whole peas, raw/dehulled peas, extruded/dehulled peas and autoclaved air-classified pea protein was determined. Digestibility of the protein component was uniformly high for all pea ingredients (90.9,94.6%), regardless of the processing treatment. Autoclaving or extrusion increased starch digestibility by 41,75% (P , 0.05), which consequently increased energy and dry matter digestibility of whole and dehulled peas. Autoclaved air-classified pea protein had superior protein (94.6%), energy (87.0%) and dry matter (84.0%) digestibility (P , 0.05). It was demonstrated that inclusion of 25% dehulled peas, 20% air-classified pea protein or 20% canola meal fines was feasible in trout diets allowing for replacement of soya bean meal. The data showed no difference (P , 0.05) in feed intake, final weight and specific growth rate (SGR) measurements, and feed utilization was not compromised with inclusion of pea or canola meal products as the primary plant ingredient. It was concluded that dehulled peas, air-classified pea protein and canola meal fines are suitable ingredients for use in trout diet formulation at a level of 20%. [source]