Bioavailability Of Starch Research Articles

Effects of rosemary extract addition on starch bioavailability and antioxidant properties of extruded pet foods

This study aimed to investigate the effects of rosemary extract (RE) addition on the starch digestion and antioxidant properties of extruded pet foods. Pet foods were extruded using rice, round pea (RP), and wrinkled pea (WP) flours as the sole starch sources with RE incorporated at levels of 0 (control), 1.0, 10.0, and 30.0 g/kg (RE0, RE1, RE10, and RE30, respectively). High-amylose WP pet food exhibited lower damaged/gelatinized starch content compared with rice and RP pet foods. The total phenolic contents and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability of the pet foods notably increased after the addition of RE, showing a clear upward trend as the incorporation level was elevated. RE10 (except for rice) and RE30 significantly decreased the starch digestibility of pet foods according to in vitro testing, with the greatest reduction observed for the high-amylose WP sample. Although RE1 did not significantly impact the overall in vitro and in vivo starch digestibility, the treatment consistently postponed the peak times of postprandial blood glucose responses to all the three extruded diets in beagles. The results indicated that RE effectively enhanced the antioxidant properties of extruded pet foods and slowed starch digestion rates.

Co-ingestion of Cereals and Legumes during Infant Complementary Feeding: Starch and Protein in vitro Digestion.

This study explores the impact of co-ingesting cereals and legumes on starch and protein during simulated infant in vitro digestion. Various legumes (chickpeas, lentils, peas) were added to cereals (durum wheat, brown rice, white maize), and their effects on starch and protein hydrolysis were analyzed. Substituting 50% of cereal with legumes increased proteins, minerals, and dietary fiber. Infant food with legumes exhibited smoother pasting properties. Legumes in cereal purées led to varying starch hydrolysis trends, with the lowest values in durum wheat with chickpea and all cereal blends with peas. Resistant starch levels exceeding 50% were found in infant food samples. Digested protein hydrolysis increased with legumes in durum wheat, except for peas. Brown rice mixtures decreased significantly compared to the control with chickpeas (61%) and peas (42%), while lentil blends increased by 46%. Legumes generally did not significantly affect starch bioavailability, even with α-amylase inhibitors. Lentil-cereal purées could enhance infant food nutritional value.

The effect of reducing starch bioavailability using organic acids on rumen fermentation and ruminant performance: A meta-analysis

Starch is an important nutrient in ruminants as an energy source. Utilizing organic acids to reduce starch bioavailability offers a safer approach to sustainable ruminant health and productivity. However, the inconsistent results obtained from published studies necessitate integration through meta-analysis to determine the actual effects. This study aimed to evaluate the effect of reducing starch bioavailability using organic acids on rumen fermentation and ruminant performance by meta-analysis. Hedges’ meta-analysis was conducted by using a random effect. A total of 14 articles were selected from the Scopus platform, with 23 comparative studies. This meta-analysis revealed that starch modification using organic acids influenced rumen fermentation. In vitro studies demonstrated a significant increase (p<0.01) in rumen pH and a reduction in ammonia (NH3) and total volatile fatty acids (VFA) levels (p<0.01). Partial VFA components, including butyrate, iso-butyrate, valerate, and iso-valerate, also showed significant decreases (p<0.01). Total protozoa also obtained a significant decrease (p<0.001). Moreover, in vivo trials indicated ruminant performance with increased milk fat content (p<0.05). In conclusion, the intervention of organic acids for reducing the bioavailability starch in rumen is effectively optimizes rumen health by maintaining fermented products within the normal range and increasing ruminant productivity.

How cereal flours, starters, enzymes, and process parameters affect the in vitro digestibility of sourdough bread

Digestibility of leavened baked goods relies on multiple factors: starch bioavailability and protein hydrolysis during food processing and digestion, presence of antinutritional factors, and satiety and gastrointestinal symptoms after intake. Several studies highlighted that bread digestibility might be positively affected by long-time sourdough fermentation. Nevertheless, most research is focused on single factors and their effect on digestibility, excluding the potential complementary effects of more than one factor. In this work, a multitude of factors influencing the the in vitro starch and protein digestibility and predicted glycemic index were assessed simultaneously. Forty-six different breads made with various raw material/ingredients (flour, enzymes, lactic acid bacteria cytoplasmic extracts and gluten), type of sourdoughs (fresh or commercial liquid or dried), strains of lactic acid bacteria and yeasts, and time and temperature of fermentation, were preliminarily investigated. Further selection of optimal conditions was based on statistical analysis and final breads were further characterized for their peptide profiles, total free amino acids and quality indexes of the digestible protein fraction.Among the factors considered, results identified a claimed in vitro digestibility for breads made with whole wheat, spelt, and rye flours, obtained with lactic acid bacteria strains selected for the peptidase activity, added of fungal proteases, and fermented at the optimal temperature of 37 °C.

Food Matrix Effects for Modulating Starch Bioavailability.

As the prevalence of obesity and diabetes has continued to increase rapidly in recent years, dietary approaches to regulating glucose homeostasis have gained more attention. Starch is the major source of glucose in the human diet and can have diverse effects, depending on its rate and extent of digestion in the small intestine, on postprandial glycemic response, which over time is associated with blood glucose abnormalities, insulin sensitivity, and even appetitive response and food intake. The classification of starch bioavailability into rapidly digestible starch, slowly digestible starch, and resistant starch highlights the nutritional values of different starches. As starch is the main structure-building macroconstituent of foods, its bioavailability can be manipulated by selection of food matrices with varying degrees of susceptibility to amylolysis and food processing to retain or develop new matrices. In this review, the food factors that may modulate starch bioavailability, with a focus on food matrices, are assessed for a better understanding of their potential contribution to human health. Aspects affecting starch nutritional properties as well as production strategies for healthy foods are also reviewed, e.g., starch characteristics (different type, structure, and modification), food physical properties (food form, viscosity, and integrity), food matrix interactions (lipid, protein, nonstarch polysaccharide, phytochemicals, organic acid, and enzyme inhibitor), and food processing (milling, cooking, and storage).

Inhibitory effect of chestnut (Castanea mollissima Blume) inner skin extract on the activity of α-amylase, α-glucosidase, dipeptidyl peptidase IV and in vitro digestibility of starches

This study aimed to investigate the inhibitory effect of chestnut inner skin extract (CISE) on the activity of postprandial blood sugar-related enzymes. In total, 12 flavonoids were identified by HPLC-TOF-MS. CISE showed strong and weak inhibition on α-amylase and α-glucosidase, with the IC50 of 27.2 and 2.3 μg/mL, respectively. The inhibition modes of CISE against α-amylase and α-glucosidase were mixed-type and non-competitive type, respectively. Epicatechin gallate noncompetitively inhibited α-amylase, α-glucosidase and dipeptidyl peptidase IV (DPP-IV). Analysis by ultraviolet–visible spectroscopy, fluorescence spectroscopy and circular dichroism suggested that flavonoids altered the hydrophobicity and microenvironment of these enzymes. CISE decreased the starch bioavailability by reducing the enzymatic hydrolysis rate and increasing the fraction of undigested starch. The extract reduced the rapidly digestible starch and increased the resistant starch after incorporation into A-, B- or C- crystallinity starch. Thus, the chestnut inner skin is a useful resource for regulating postprandial blood sugar level.

Influence of Processing Methods on Food Components and Glycaemic Index of Cassava-based Traditional Foods

Processing methods affect starch hydrolysis, digestibility, absorption and glycaemic index (GI) of food. Although some studies have reported on the effect of boiling, frying, roasting and baking on glycaemic index of traditional staples, there is limited information on the contribution of drying, fermentation, boiling and steaming on starch bioavailability and glycaemic index. This research work aimed at determining the effect of fermentation, steaming, boiling and drying on starch bioavailability and predicted GI of some cassava-based traditional foods consumed in Ghana. The total starch, amylose, amylopectin, dietary fibre and predicted glycaemic index of the intermediate and finished products were determined according to standard protocols. The analysis established that steaming and boiling increase GI of foods, fermentation has no significant influence on predicted GI of fermented steamed products, and drying has no substantial effect on predicted GI of cassava flour. However, staples or products prepared from solar dried cassava flour would have higher predicted GIs than those of sun dried cassava flour. This work has also provided evidence in support of the fact that total starch and amylopectin give rise to an increase in GI whereas amylose and dietary fibre contents contribute to a decrease in GI of foods. The predicted GIs of raw cassava, boiled cassava (<i>ampesi</i>), <i>akyeke</i>, cooked <i>kokonte</i> with sun dried flour and cooked <i>kokonte</i> with solar dried flour were found to be (47.75%), (77.30%), (79.05%), (40.20%) and (61.11%), respectively. Temperature plays a significant role in breaking hydrogen bonds in food molecules causing the release of glucose and subsequently affecting GI. The GI data of these staples may be used in conjunction with other food composition tables for healthy food choices and nutritional counselling. Processors can incorporate more fibre or amylose-containing crops into food products as well as ensure the use of sun or solar drying to produce low glycaemic index food products.

Digestibility of dry matter and bioavailability of starch of various types of grain in the rumen

The constant introduction of a huge amount of concentrates at the stage of growing and fattening animals can lead to diseases associated with non-compliance with the feeding technique (acidosis). In this regard, the study of metabolism, destruction of dry matter, as well as starch in various feeds of grain origin, including those growing in the Orenburg region and contributing to the acidification of the rumen, is essential and necessary to increase feed efficiency. The highest rate of starch digestion six hours after incubation was in rye, exceeding the similar values of other crops by 0.4-1.3%. Further, two groups of crops should be distinguished with almost the same rate of starch digestion: these are wheat, imported barley, oats and chickpeas, domestic barley. It should be noted that the lowest rate of starch digestion was characteristic of the latter group (6.0%). The need to study the decay of the components of cereals with their active feeding to cattle is important. Including it is necessary to consider regional peculiarities of cultivation of these crops, since the content of substances in the grain, and for the same species, varies greatly, which ultimately affects the feed efficiency.

Evaluation of the method of reducing the bioavailability of starch in the rumen of ruminants

Prevention of metabolic acidosis, tympania of the rumen during the fattening of cattle is an important issue in the production of beef. Researchers are actively searching for available substances and evaluating their effect on fermentation of the ruminant cicatrix. Perspective in this regard may be the use of organic acids in animal nutrition. The following samples were prepared for the study: crushed barley + distilled water (control); crushed barley + 0.5% solution of lactic acid; crushed barley + 1.0% solution of lactic acid; crushed barley + 2% solution of lactic acid. The digestibility of dry matter and starch in the artificial scar (in vitro), depending on the concentration of lactic acid and 30 min exposure, was studied by exposure for 3 and 6 hours. The experiment found that the processing of ground barley with 0.5%, 1% and 2% lactic acid contributed to the decrease in digestibility of dry matter by 26.7-32.2% and starch by 16.1-21.1% 3 hours after incubation. A 0.5-1.0% solution of lactic acid is optimal for use, as it effectively reduces the availability of starch for the cicatricial microflora of ruminants.

Fish Protein and Lipid Interactions on the Digestibility and Bioavailability of Starch and Protein from Durum Wheat Pasta.

This research focussed on the utilisation of salmon protein and lipid to manipulate pasta’s glycaemic index and protein digestibility. Salmon fish (Oncorhynchus tschawytscha) powder (SFP) supplemented pasta flour in amounts from 5% to 20% (w/w). Inclusion of SFP lead to a significant reduction in starch digestibility and hence the potential glycaemic values of pasta (experimental pasta being up to 143% lower than control values). SFP addition to pasta increased the release of phenolic compounds from pasta during both gastric digestion (179%) and pancreatic digestion (133%) in comparison to the control sample. At the same time, the antioxidant activity of the digested pasta was increased by up to 263% (gastric) and 190% (pancreatic) in comparison to durum wheat pasta alone. Interestingly, although protein levels increased with incorporation of SFP, the digestibility values of the protein decreased from 86.41% for the control pasta to 81.95% for 20% SFP pasta. This may indicate that there are interactions between phenols and protein in the pasta samples which affect overall protein digestibility levels.

Impact of food structure and cell matrix on digestibility of plant-based food

The effect of plant attributes, such as the cell wall and fibrous tissue structure, on human digestion, can be exploited to modify the digestive quality of processed foods. To understand the digestive property of plant-based food, recent studies employing in vitro simulated digestion systems are highlighted and its relatedness to structural aspects are summarized in this review. The bioaccessibility and bioavailability of starch (as a digestible carbohydrate), lipids, proteins and functional phytochemicals, such as carotene, are mentioned as an indicator of plant-based food digestibility, including pasta as an example of plant-based processed foods. The modification of food matrices and structure design to control the bioavailability of pharmaceuticals and nutraceuticals is also mentioned.

Digestibility of starches isolated from stem and root tubers of arracacha, cassava, cush–cush yam, potato and taro

Digestibility of arracacha, cassava, cush‐cush yam, potato and taro starches was evaluated. In vitro (potentially-available starch and total resistant starch) and in vivo digestibility in the rice weevil (Sitophilus oryzae) bioassay (survival, weight variation, α‐amylase like activity [ALA], and uric acid excretion [UAE] as biomarkers) were estimated. In in vitro assays, all starches presented high resistant starch content (14–56%, dry basis), except for cassava starch. In in vivo assays, cush–cush yam and potato starches promoted higher ALA (>3 times) and UAE (>4 times) compare to a reference diet (cornstarch), in agreement to their low digestibility. These two biomarkers were related with resistant starch (r>0.81) and could be used to predict the starch bioavailability. This study demonstrates that the use of both in vitro and in vivo assays allows a better evaluation of starch digestibility, and may help to elucidate the final metabolic fate of starch digestion products.

Catalytic hydrolysis of starch for biohydrogen production by using a newly identified amylase from a marine bacterium Catenovulum sp. X3

An identified cold-adaptive, organic solvents-tolerant alkaline α-amylase (HP664) from Catenovulum sp. strain X3 was heterologously expressed and characterized in E. coli, and it was further applied to starch saccharification for biohydrogen production. The recombinant HP664 belongs to a member of glycoside hydrolase family 13 (GH13), with a molecular weight of 69.6kDa without signal peptides, and also shares a relatively low similarity (49%) to other reported amylases. Biochemical characterization demonstrated that the maximal enzymatic activity of HP664 was observed at 35°C and pH 9.0. Most metal ions inhibited its activity; however, low polar organic solvents (e.g., benzene and n-hexane) could enhance the activity by 35–50%. Additionally, HP664 also exhibited the catalytic capability on various polysaccharides, including potato starch, amylopectin, dextrin and agar. In order to increase the bioavailability of starch for H2 production, HP664 was utilized to elevate fermentable oligosaccharide level, and the results revealed that the maximal hydrolytic percentage of starch was up to 44% with 12h of hydrolysis using 5.63U of HP664. Biohydrogen fermentation of the starch hydrolysate by Clostridium sp. strain G1 yielded 297.7mL of H2 after 84h of fermentation, which is 3.73-fold higher than the control without enzymatic treatment of HP664.

Performance of broiler chickens offered nutritionally-equivalent diets based on two red grain sorghums with quantified kafirin concentrations as intact pellets or re-ground mash following steam-pelleting at 65 or 97°C conditioning temperatures

The Liverpool Plains is a fertile agricultural region in New South Wales, Australia. Two sorghums from the 2009 Liverpool Plains harvest, sorghums #3 and #5, were extensively characterised which included concentrations of kafirin and phenolic compounds plus rapid visco-analysis (RVA) starch pasting profiles. Diets based on these two sorghums were formulated to be iso-nitrogenous and iso-energetic and were offered to male Ross 308 broiler chicks from 7 to 28 days post--hatch as either intact pellets or reground mash following steam-pelleting at conditioning temperatures of either 65 or 97°C. Thus the feeding study consisted of a 2 × 2 × 2 factorial array of dietary treatments: two sorghum varieties, two feed forms and two conditioning temperatures. Each of the eight treatments was replicated six times with six birds per replicate cage. Assessed parameters included growth performance, nutrient utilisation, apparent starch and protein (N) digestibility coefficients and disappearance rates from the distal jejunum and distal ileum. Intact pellets supported higher (P < 0.001) feed intakes and weight gains by 9.83 and 9.08%, respectively, than reground mash diets. Feed conversion ratios of broilers offered diets steam-conditioned at 97°C were 2.46% inferior (P < 0.001) in comparison to 65°C diets and both apparent metabolizable energy (AME) and N-corrected AME (AMEn) were compromised. Broilers offered sorghum #3-based diets significantly (P < 0.001) outperformed their sorghum #5 counterparts in terms of weight gain by 3.75% (1,334 versus 1,223 g/bird), FCR by 4.81% (1.524 versus 1.601), AME by 1.06 MJ (13.61 versus 12.55 MJ/kg), ME:GE ratio (ME:GE) by 4.81% (0.806 versus 0.769) and AMEn by 1.03 MJ (12.38 versus 11.35 MJ/kg). The inferiority of sorghum #5 appeared to be associated with higher concentrations of kafirin (61.5 versus 50.7 g/kg) and conjugated phenolic acids, including ferulic acid (31.1 versus 25.6 µg/g). There were no significant differences in jejunal and ileal starch and protein (N) digestibility coefficients between the two sorghums. However, starch to protein (N) disappearance rate ratios from the distal jejunum were significantly (P < 0.001) correlated with ME:GE and AME. The multiple linear regression equations indicated that energy utilisation was enhanced by coupling rapidly digestible protein with slowly digestible starch, which suggests that bilateral bioavailability of starch and protein is pivotal to efficient energy utilisation.

In vitro and in vivo digestibility of corn starch for weaned pigs: Effects of amylose:amylopectin ratio, extrusion, storage duration, and enzyme supplementation.

The objective of this study was to investigate the effects of amylose (AM):amylopectin (AP) ratio, extrusion, storage duration, and enzyme supplementation on starch digestibility of corn. Three corn varieties with high (0.60; HA), medium (0.44; MA), and low (0.39; LA) AM:AP ratios, respectively, were selected from 74 corn samples to evaluate the in vitro and in vivo digestibility of starch. In Exp. 1, during wk 4 after extrusion, resistant starch (RS) content of the 3 selected corn varieties (LA, MA, and HA) increased (P < 0.05) each week and starch digestibility in vitro decreased as storage time increased (P < 0.05). The AM:AP ratio affected the formation of RS (P < 0.01). The RS content of the 3 corn varieties was ranked as LA < MA < HA in each week (P < 0.05). Correlation analysis showed that AM:AP ratio and storage duration were both positively correlated with RS content (P < 0.01). Furthermore, a significant quadratic relation was found between storage duration and RS content in each corn variety as well as storage duration and digestibility. Starch digestibility was negatively correlated with RS content (P < 0.001). In Exp. 2, digestion trials were performed on cannulated pigs with BW of 13.20 ± 0.94 kg. Extrusion increased ileal digestibility of GE and starch of either HA or LA compared with the enzyme-supplemented diets (P < 0.001). Enzyme supplementation did not improve ileal energy and starch digestibility. The ileal digestibility of starch and GE of LA varieties was greater than HA samples (P < 0.05). The results implied that AM:AP ratio and storage duration after extrusion may be important determinants of RS formation and digestibility of starch for corn. In addition, RS content could be an important indicator of digestibility of starch in extruded corn. Using a lower AM:AP ratio corn or reducing the storage duration of extruded corn would help to reduce the formation of RS and improve the starch bioavailability of corn for piglets.

Influence of Amylose Starch on Development and Lifespan of Fruit Fly Drosophila Melanogaster

Last years, the concept of resistant starch (RS) has evoked a new interest in researchersin the context of bioavailability of starch and its use as a source of dietary fiber. Based on clinicaland animal research, RS has been proposed to be the most potentially beneficial starch fraction forhuman health. In this study, the effects of amylose starch as a fraction of RS on development andlifespan of fruit fly Drosophila melanogaster were investigated. In both Canton S and w1118 strains, thediet with 20% amylose RS delayed fly development, increased triacylglyceride level in the body ofadult insects and reduced their lifespan compared to the diet with 4% amylose starch. Thus, ourdata clearly demonstrate that amylose starch at high concentrations may negatively affect fruit fly

Reply to Wollstonecroft et al.: Cooking increases the bioavailability of starch from diverse plant sources

We thank Wollstonecroft et al. for supporting the evidence that not all calories are equal (1). We found that the bioavailability of calories from lean beef (Bos taurus) and sweet potato (Ipomoea batatas) increased with food processing (2). For both foods, cooking had a larger impact on bioavailability than pounding, and when these processing methods were applied in combination, cooking improved a pounded diet whereas pounding did not improve a cooked diet. Our findings emphasize that the biochemical assays used in the production of modern nutrition labels do not fully account for the energetic significance of food processing. Such assays ignore important costs of the digestive process that are typically lowered by processing, including diet-induced thermogenesis and nutrients metabolized by gut bacteria instead of the human host.

The Role of Bile and Pancreatin in Improving the In Vitro Bioavailability of Lycopene and Starch in Extruded Snacks Containing Tomato Paste Powder

Nutritionally enhanced extruded snack foods enriched with tomato paste powder were produced that contained lycopene and fiber. To simultaneously measure the in vitro bioavailability of lycopene and starch from the snacks, a digestion model was developed by using various concentrations of bile (0 to 20 mg/ml) and pancreatin (0, 0.4, 2.4, 4.8, and 6 mg/ml). In vitro bioavailability of starch was determined based on the glucose released and, for lycopene, the amount transferred to the micellar phase of digesta. Furthermore, the digestion was monitored by measuring the proportion of solids remaining at the end of digestion. The amount of glucose released from the starch after 120 min of digestion varied between 683 and 885 mg/g starch at different bile and pancreatin concentrations. The presence of bile reduced the amount of pancreatin needed to maximize starch digestibility. The proportion of micellar lycopene increased from 5% to 43% with increases in both bile and pancreatin concentrations. At constant pancreatin concentration, increases in bile concentration enhanced the in vitro bioavailability of lycopene by up to fivefold, while at constant bile concentration, 1.5-fold increase was observed with the increases in pancreatin used. The proportion of solids remaining at the end of digestion varied from 14% to 70%. Increasing the bile and pancreatin concentration enhanced the digestion of the snack. In conclusion, the maximum amount of potentially bioavailable starch and lycopene in this study was obtained by using 4.8 mg/ml pancreatin and 10 mg/ml bile. Furthermore, the results suggest that bile and pancreatin collaborated in the digestion of both starch and lycopene present in the enriched snack.

Production of bioethanol from steam-flaked sorghum and maize

The aim was to study the effect of steam-flaking of sorghum and maize on bioethanol production and the performance of their ground meals during liquefaction, saccharification and yeast fermentation. A bifactorial experiment with a level of confidence of P < 0.05 was designed to study differences between sorghum and maize and the effectiveness of steam-flaking. Grains were steam-flaked to increase starch bioavailability and disrupt the protein matrix that envelopes starch granules. The steam-flaked sorghum had significantly higher and faster starch hydrolysis compared to the regular kernel during liquefaction. This hydrolysate contained about 33% more reducing sugars compared to the untreated counterpart and similar amounts compared to both maize treatments. At the end of saccharification, the sorghum spent grains contained more residual starch compared to the maize counterparts. Steam-flaking significantly reduced residual starch especially in steam-flaked sorghum. The final glucose concentration in steam-flaked sorghum was similar to the concentration obtained in both maize mashes and 26.5% higher compared to the untreated sorghum. The yield of ethanol in steam-flaked sorghum was 44.2% higher compared to the untreated counterpart and similar to both maize treatments. Therefore, steam-flaking is a treatment useful to increase ethanol production especially in sorghum due to the higher starch bioavailability.

Impact of processing technique on the apparent bioavailability of cooking banana (matooke) starch

The aim of the study was to compare the apparent bioavailability of starch in raw, cooked and extruded matooke flours using weanling mice. Two control and three test groups consisting of seven mice each (initial body weight of 21.32 ± 1.05 g) were fed diets incorporating soluble unavailable starch (Control I), soluble starch (Control II) and raw, cooked and extruded matooke flours as carbohydrate bases, for three weeks. The growth rate, food intake, adipose tissue size and 12 h fasting glucose levels were measured. The mean values of the growth parameters were separated by ANOVA using GENSTAT statistical package. There was a significant difference (P<0.001) in food intake between the control and test groups. The mice fed on solubilised matooke starches (cooked and extruded) exhibited significantly higher (P<0.001) growth rates than the ones fed on raw starch, showing a higher apparent bioavailability of the former flours. The mice fed on Control I appeared malnourished despite an excessively high food intake. The raw matooke group displayed less pronounced symptoms of malnourishment despite recording the highest weight loss. The fat pad sizes were in agreement with the growth rate data. The glucose levels, though on the lower side particularly in the Control I and raw matooke flour groups, were within the normal range. The results demonstrated that solubilised matooke starches adequately met the energy requirement of a growing animal. Nonetheless extrusion cooking appeared to confer a marginal advantage over the cooked flour, due to extruded flour’s lower peak viscosity. This advantage would be enhanced in humans if the rations are taken as porridges. Key words: Starch-bioavailability, matooke, protein-energy malnutrition.