Optimization of formulation and processing conditions for the production of functional noodles containing orange-fleshed sweet potatoes and biofortified beans.

The global demand for noodles continues to increase due to their convenience, wide appeal, and affordability. Instant noodles, in particular, are popular for their easy preparation. With annual consumption reaching 106 billion servings in 2019, there is a growing awareness of the importance of healthy food options. However, most noodle types currently available commercially are of low nutritional value. This study sought to develop a protocol for the production of functional noodles consisting of orange-fleshed sweet potatoes (OFSP) puree and biofortified bean powder (BBP). Response surface methodology (RSM) was used to optimize product formulation and processing parameters. Reduced quartic models were found to adequately represent the relationship between dependent variables (hardness, moisture, protein, dietary fiber, iron, and zinc content) and independent variables (dough thickness, drying temperature, and drying time). R 2 values were 0.86-0.99, with a nonsignificant lack-of-fit (p < .05). Using numerical optimization, the optimal protocol for the production of functional noodles was determined to include formulation consisting of wheat 73%, OFSP 21.5%, and BBP 5.5%; dough thickness of 2.0 mm; drying temperature and time of 80.0°C and 143.4 min, respectively. These conditions yielded noodles with 5.9% moisture, 11.0 N hardness, 34.5% protein, 11.9% dietary fiber, 86.9 ppm (parts per million) iron, and 50.53 ppm zinc, with a desirability value of 0.82. Experimental validation demonstrated no significant difference from predicted values. Sensory evaluation rated the noodles as acceptable to consumers, with an overall acceptability of 7.8 on a 9-point hedonic scale. These results show the potential of OFSP and BBP as ingredients for acceptable and nutrient-rich noodles.

Influence of ripeness stage on the bioactive compounds' contents and antioxidant activities of Solanum anguivi Lam. fruits accessions.

Solanum anguivi Lam. fruits (SALF) possess bioactive compounds, such as phenolics, alkaloids, saponins, flavonoids, and vitamin C, that are beneficial for preventing oxidative stress-related diseases. It has been documented that ripeness stage influences the nutritional quality of fruits. However, there is limited information on the effect of the ripeness stages (unripe, yellow, orange and red) on the bioactive compounds' contents (BCC) and antioxidant activity (AA) of SALF. We investigated the effect of ripening on the BCC and AA of different SALF accessions. Spectrophotometry was used to determine SALF's total contents of phenolics, flavonoids, saponins, vitamin C, and AA and gravimetry for total alkaloids. The AA was determined as free radical scavenging activity (FRSC) and total antioxidant capacity (TAC). The total phenolics (7.6-22.6 mg gallic acid equivalent/g DW), flavonoids (1.3-4.1 mg quercetin equivalent (QE)/g DW), saponins (44.8-152.5 mg diosgenin equivalent/g DW), vitamin C (2.2-6.4 mg ascorbic acid equivalent/g DW), alkaloids (141.2-296.9 mg/g DW), FRSC (1.5-66.2 %) and TAC (0.1-14.2 mg QE/g DW) significantly differed among the ripeness stages. Fruits in the unripe stage were rich in phenolics, flavonoids, and AA; in the red stage in alkaloids and vitamin C; and in the orange stage, in saponins and flavonoids. The AA had strong positive correlations with total flavonoids and phenolics (r = 0.72 and 0.81, respectively) and a moderate negative correlation with total alkaloids (r = -0.67). Overall, unripe stage fruits had the highest AA and total phenolics and thus may have the highest health-promoting properties. Botanists and farmers may, therefore, focus on harvesting and trading SALF to markets/consumers while still unripe.

Drying behaviour and optimization of drying conditions of pineapple puree and slices using refractance window drying technology.

Refractance window drying technology can be used to produce high quality dried fruit products due to its excellent retention of heat sensitive nutrients, organoleptic properties and bioactive compounds. This study optimised conditions for drying of pineapple slices and puree using RWDT. i-optimal design in Design Expert software was used to generate temperature-thickness combinations in form of runs. The independent factors considered included drying temperature (70-90 °C) and thickness (2-3 mm), and the responses included drying time and vitamin C concentration. The optimum solutions generated for RW drying temperature and pulp thickness were 86.2 °C and 2.9 mm for puree and 78.9 °C and 2 mm for slices. The drying times for puree and slices were 58 and 96 min, respectively with corresponding vitamin C content of 64.88 and 46.83 mg/100 g. Drying kinetics of puree and slices were determined at optimal conditions. Drying was found to follow Modified Midilli et al. Model. Pineapple powder obtained using optimal RWD conditions had low water activity (0.41), high solubility (74.64%) and dehydration ratio (4.12). Pineapple reconstituted drinks were developed and evaluated for consumer preference. Acceptability was highest at 15% inclusion of pineapple powder. Supplementary Information: The online version contains supplementary material available at 10.1007/s13197-021-05302-2.

Solanum anguivi Lam. Fruits: Their Potential Effects on Type 2 Diabetes Mellitus.

Type 2 diabetes mellitus (T2DM) is a complex metabolic disorder of glucose homeostasis associated with a status of insulin resistance, impaired insulin signaling, ß-cell dysfunction, impaired glucose and lipid metabolism, sub-clinical inflammation, and increased oxidative stress. Consuming fruits and vegetables rich in phytochemicals with potential antidiabetic effects may prevent T2DM and/or support a conservative T2DM treatment while being safer and more affordable for people from low-income countries. Solanum anguivi Lam. fruits (SALF) have been suggested to exhibit antidiabetic properties, potentially due to the presence of various phytochemicals, including saponins, phenolics, alkaloids, ascorbic acid, and flavonoids. For the saponin fraction, antidiabetic effects have already been reported. However, it remains unclear whether this is also true for the other phytochemicals present in SALF. This review article covers information on glucose homeostasis, T2DM pathogenesis, and also the potential antidiabetic effects of phytochemicals present in SALF, including their potential mechanisms of action.

Bean-based nutrient-enriched puffed snacks: Formulation design, functional evaluation, and optimization.

School-age children frequently consume snacks. However, most of the snacks they consume are of low nutritional quality. The objective of this study was to develop a nutrient-rich and acceptable extruded bean-based snack, which could contribute to improved nutrient intake, especially for school-age children. Snack formulations developed from Roba1 beans, maize, orange-fleshed sweet potato, and amaranth mixtures, and processed in a twin-screw extruder, were evaluated and optimized for nutritional, textural and sensory properties. High proportion of beans in the formulation was associated with high protein, iron, zinc, and dietary fiber content. An optimal formulation (82.03:10: 5:2.97; beans, maize, OFSP, amaranth), containing 20.38 g, 4.12 g, 4.83 mg, and 1.51 mg per 100 g, of protein, dietary fiber, iron, and zinc, respectively, was obtained. The snacks were crunchy and moderately acceptable with average sensory scores of 6 on a 9-point hedonic scale, and hardness 26.6 N. Nutrient contribution 43, 19, and 12% for protein, iron, and zinc, respectively, to children aged 6 to 8 years; and 24, 19, and 7.6%, respectively, to children aged 9 to 12 years from a 40 g serving was estimated from the snack. The results demonstrate the potential of using extrusion to produce nutrient enriched value-added food products from blends of iron-rich beans and common staples.

Fruit and vegetable consumption, leisure-time physical activity, and sedentary behavior among children and adolescent students in Uganda.

INTRODUCTION: Fruit and vegetable (FV) intake and participation in leisure-time physical activity (PA) and in sedentary behavior in accordance with the recommendations are met in a minority of populations including children and adolescents. OBJECTIVE: To describe the frequency of FV intake, leisure-time PA, and sedentary behavior, assess compliance with international recommendations, and how selected factors are associated with these recommendations. METHODS: The FV consumption and PA questionnaire items previously assessed for reliability in a Ugandan setting were used to gather information about FV consumption, PA, and sedentary behavior among 621 children and adolescents attending schools in Kampala Uganda. The results of FV consumption and PA were categorized as adequate or inadequate while sedentary behavior was categorized as adequate or excess. The relationship between FV consumption, PA, and sedentary behavior with selected independent variables was verified by chi-square test statistic. RESULTS: Half of the participants (50%) reported inadequate fruit consumption, and 76% of them reported inadequate vegetable consumption. More children (68%) than young adolescents (52%) and older adolescents (44%) met their daily recommendation for fruit consumption. A similar trend was observed for vegetable consumption. Adequacy of FV intake was significantly associated with participant's age, level of education, school ownership, and type of school. Less of 8- to 17-year-olds (14%) than 18 years and above olds (41%) met their weekly recommendation for leisure-time PA. Majority of participants (54%) participated in acceptable levels of sedentary behaviors. Leisure-time PA was significantly associated with age category and school ownership while sedentary behavior was significantly associated with participant's age and education level. CONCLUSIONS: The intake of FV and participation in leisure-time PA was not adequate in the study population. A significant proportion of participants engaged in excess sedentary behavior. Developing and implementing strategies to increase FV intake and PA among children and adolescents in schools should be a national priority.

Multi-response optimization of extrusion conditions of grain amaranth flour by response surface methodology.

The study was designed to optimize extrusion processing conditions for production of instant grain amaranth flour for complementary feeding. Multi-response criteria using response surface methodology and desirability function analysis were employed during the study. The central composite rotatable design (CCRD) was used to determine the level of processing variables and to generate the experimental runs. The process parameters tested included extrusion temperature (110-158°C), screw speed (40-52 Hz), and feed moisture content (11%-16%), while response variable was protein digestibility, sensory acceptability, water absorption index, water solubility index, bulk density, and viscosity. Data obtained from extrusion were analyzed using response surface methodology. Data were fitted to a second-order polynomial model, and the dependent variables expressed as a function of the independent variables. Analysis of variance (ANOVA) revealed that extrusion parameters had significant linear, quadratic, and interactive effects on the responses. Numerical optimization indicated that the optimum extrusion parameters were extrusion temperature of 150°C, extrusion speed (screw speed) of 50 Hz, and feed moisture content of 14.41%. The responses predicted for optimization resulted in protein digestibility 81.87%, water absorption index 1.92, water solubility index 0.55, bulk density 0.59 gm/L, viscosity 174.56 cP (14.55 RVU), and sensory acceptability score of 6.69, with 71% desirability.

Prediction equations for body composition of children and adolescents aged 8-19 years in Uganda using deuterium dilution as the reference technique.

BACKGROUND AND AIMS: Body composition is important as a marker of both current and future health status. Bioelectrical impedance analysis (BIA) is a simple and accurate method for estimating body composition in field, clinical and research settings, if standard protocol procedures are followed. However, BIA requires population-specific equations since applicability of existing equations to diverse populations has been questioned. This study aimed to derive predictive equations for Total Body Water (TBW), Fat Free Mass (FFM) and Fat Mass (FM) determinations with BIA and anthropometric measurements in a population of children and adolescents aged 8-19 years in Uganda. METHODS: A cross-sectional study was conducted among 203 children and adolescents aged 8-19 years attending schools in Kampala district (also referred to as Kampala city since the city is conterminous with the district), Uganda through a two-stage cluster sample design. Deuterium dilution method (DDM) was used as the reference measure while BIA and anthropometric measures were used to create the new body composition prediction equations through multivariate regression. RESULTS: The new prediction equations explained 88%, 87% and 71% of the variance in TBW, FFM % and of FM respectively with no statistical shrinkage upon cross-validation. The linear regression models proposed in this study were well adjusted with respect to TBW, FFM and FM. Log of TBW obtained by DDM = 0.0129 × Impedance index + 0.0055 × Age + 0.0049 Waist Circumference + 0.1219Ht2 + 2.0388. Log of FFM obtained by DDM = 0.0197 × FFM obtained by BIA - 0.0181 sex code - 0.00055 × Impedance + 3.1761. Log of FM obtained by DDM = 0.0634 × FM obtained by BIA - 0.1881 sex code + 0.0252 × Weight + 0.5273. CONCLUSION: The use of these equations for more accurate body composition assessment may facilitate identification of effective intervention strategies to prevent or combat overweight and obesity among children and adolescents. They may also assist in treatment of conditions where more accurate information on body composition measures is required.

Assessing the reliability of FTIR spectroscopy measurements and validity of bioelectrical impedance analysis as a surrogate measure of body composition among children and adolescents aged 8-19 years attending schools in Kampala, Uganda.

BACKGROUND: Accurate measurement of body composition in children and adolescents is important as the quantities of fat and fat-free mass have implications for health risk. The objectives of the present study were: to determine the reliability of Fourier Transform Infrared spectroscopy (FTIR) measurements and; compare the Fat Mass (FM), Fat Free Mass (FFM) and body fat percentage (%BF) values determined by bioelectrical impedance analysis (BIA) to those determined by deuterium dilution method (DDM) to identify correlations and agreement between the two methods. METHODS: A cross-sectional study was conducted among 203 children and adolescents aged 8-19 years attending schools in Kampala city, Uganda. Pearson product-moment correlation at 5% significance level was considered for assessing correlations. Bland Altman analysis was used to examine the agreement between of FTIR measurements and between estimates by DDM and BIA.. Reliability of measurements was determined by Cronbach's alpha. RESULTS: There was good agreement between the in vivo D2O saliva enrichment measurements at 3 and 4 h among the studied age groups based on Bland-Altman plots. Cronbach's alpha revealed that measurements of D2O saliva enrichment had very good reliability. For children and young adolescents, DDM and BIA gave similar estimates of FFM, FM, and %BF. Among older adolescents, BIA significantly over-estimated FFM and significantly under-estimated FM and %BF compared to estimates by DDM. The correlation between FFM, FM and %BF estimates by DDM and BIA was high and significant among young and older adolescents and for FFM among children. CONCLUSIONS: Reliability of the FTIR spectroscopy measurements was very good among the studied population. BIA is suitable for assessing body composition among children (8-9 years) and young adolescents (10-14 years) but not among older adolescents (15-19 years) in Uganda. The body composition measurements of older adolescents determined by DDM can be predicted using those provided by BIA using population-specific regression equations.

Physico-chemical properties and extrusion behaviour of selected common bean varieties.

BACKGROUND: Extrusion processing offers the possibility of processing common beans industrially into highly nutritious and functional products. However, there is limited information on properties of extrudates from different bean varieties and their association with raw material characteristics and extrusion conditions. In this study, physico-chemical properties of raw and extruded Bishaz, K131, NABE19, Roba1 and RWR2245 common beans were determined. The relationships between bean characteristics and extrusion conditions on the extrudate properties were analysed. RESULTS: Extrudate physico-chemical and pasting properties varied significantly (P < 0.05) among bean varieties. Expansion ratio and water solubility decreased, while bulk density, water absorption, peak and breakdown viscosities increased as feed moisture increased. Protein exhibited significant positive correlation (P < 0.05) with water solubility index, and negative correlations (P < 0.05) with water absorption, bulk density and pasting viscosities. Iron and dietary fibre showed positive correlation while total ash exhibited negative correlation with peak viscosity, final viscosity and setback. Similar trends were observed in principal component analysis. CONCLUSION: Extrudate physico-chemical properties were found to be associated with beans protein, starch, iron, zinc and fibre contents. Therefore, bean chemical composition may serve as an indicator for beans extrusion behaviour and could be useful in selection of beans for extrusion. © 2017 Society of Chemical Industry.

Effect of tamarind (Tamarindus indica L.) seed on antioxidant activity, phytocompounds, physicochemical characteristics, and sensory acceptability of enriched cookies and mango juice.

Tamarind seeds are not consumed despite their high antioxidative activity. In this study, 0-10% tamarind seed powder (TSP) was incorporated into mango juice and cookies. Total phenolics (Folin-Ciocalteu assay), antioxidant activity (2,2-diphenyl-1 picrylhydrazyl (DPPH) radical scavenging assay), flavonoid (aluminum chloride assay), condensed tannins content (Vanillin-HCl assay), and consumer acceptability (n = 50) of the products were determined. TSP increased the pH and viscosity and reduced titratable acidity of juice. Incorporation of TSP increased the: total phenolic content (6.84 ± 0.21 to 88.44 ± 0.8 mg GAE/100 mL); flavonoid (4.64 ± 0.03-21.7 ± 0.36 mg CE/100 mL); condensed tannins (0.24 ± 0.01-21.81 ± 0.08 mg CE/100 mL) and total antioxidant activity (4.65 ± 0.88-21.70 ± 0.03 mg VCE/100 mL) of juice. A similar trend was observed for cookies. Maximum sensorially acceptable TSP levels were 1.5% and 6%, respectively, for juice and cookies. TSP can thus be utilized as a source of natural antioxidants in food products.

Effect of processing methods on nutritional, sensory, and physicochemical characteristics of biofortified bean flour.

Common beans (Phaseolus vulgaris L.) are rich nutritious and affordable by vulnerable groups, thus a good choice for biofortification to address malnutrition. However, increasing micronutrients content of beans, without improving micronutrients bioavailability will not improve the micronutrients status of consumers. Effect of different processing methods on the physicochemical characteristics of biofortified bean flour was determined. Processing methods used in this study were malting (48 h), roasting (170°C/45 min), and extrusion cooking using a twin screw extruder with three heating sections, the first set at 60°C, the second at 130°C, and the last one at 150°C. The screw was set at a speed of 35 Hz (123g) and bean flour moisture content was 15%. Mineral extractability, in vitro protein digestibility, pasting properties, and sensory acceptability of porridge and sauce from processed flour were determined. All processing methods significantly increased (P < 0.05) mineral extractability, iron from 38.9% to 79.5% for K131 and from 40.7% to 83.4% for ROBA1, in vitro protein digestibility from 58.2% to 82% for ROBA1 and from 56.2% to 79% for K131. Pasting viscosities of both bean varieties reduced with processing. There was no significant difference (P < 0.05) between sensory acceptability of porridge or sauce from extruded biofortified bean flour and malted/roasted biofortified bean flour. Acceptability was also not affected by the bean variety used. Mineral bioavailability and in vitro protein digestibility increased more for extruded flour than for malted/roasted flours. Sauce and porridge prepared from processed biofortified bean flour had lower viscosity (extruded flour had the lowest viscosity), thus higher nutrient and energy density than those prepared from unprocessed biofortified bean flour. Estimated nutritional contribution of sauce and porridge made from processed ROBA1 flour to daily requirement of children below 5 years and women of reproductive age found to be high. These results show that processing methods enhanced nutritional value of biofortified bean flour and that processed biofortified bean flour can be used to prepare nutrient and energy-dense gruel to improve on nutritional status of children under 5 years and women of reproductive age.

Factors influencing consumption of nutrient rich forest foods in rural Cameroon.

Studies show that a number of forest foods consumed in Cameroon are highly nutritious and rich in health boosting bioactive compounds. This study assessed the knowledge and perceptions towards the nutritional and health promoting properties of forest foods among forest dependent communities. The relationship between knowledge, perceptions and socio-demographic attributes on consumption of forest foods was also determined. A total of 279 females in charge of decision making with respect to food preparation were randomly selected from 12 villages in southern and eastern Cameroon and interviewed using researcher administered questionnaires. Multivariate logistic regression analysis was used to identify the factors affecting consumption of forest foods. Baillonella toxisperma (98%) and Irvingia gabonesis (81%) were the most known nutrient rich forest foods by the respondents. About 31% of the respondents were aware of the nutritional value and health benefits of forest foods. About 10%-61% of the respondents expressed positive attitudes to questions related with health benefits of specific forest foods. Consumption of forest foods was found to be higher among polygamous families and also positively related to length of stay in the forest area and age of respondent with consumption of forest foods. Education had an inverse relationship with use of forest foods. Knowledge and positive attitude towards the nutritional value of forest foods were also found to positively influence consumption of forest foods. Since knowledge was found to influence attitude and consumption, there is need to invest in awareness campaigns to strengthen the current knowledge levels among the study population. This should positively influence the attitudes and perceptions towards increased consumption of forest foods.

Effects of combined traditional processing methods on the nutritional quality of beans.

Consumption of dry beans is limited by long cooking times thus high fuel requirement. The bioavailability of nutrients in beans is also limited due to presence of antinutrients such as phytates and tannins. Little research has been done on combined processing methods for production of nutritious fast cooking bean flour and the effect of combined treatments on nutritional quality of beans has not previously determined. The aim of this study was to reduce cooking time and enhance the nutritional value of dry beans. Specifically to: develop protocols for production of fast cooking bean flours and assess the effect of processing on the nutritional characteristics of the flours. Dry beans (K131 variety) were soaked for 12 h; sprouted for 48 h; dehulled and steamed for 25 and 15 min for whole and dehulled beans respectively or roasted at 170°C for 45 and 15 min for whole and dehulled beans respectively. Dehulling eliminated phytates and tannins and increased protein digestibility. In vitro protein digestibility and mineral (iron and zinc) extractability were negatively correlated with tannin and phytate content. Total available carbohydrates were highest in moist heat-treated bean flours. Overall, combined processing of beans improved the nutritional quality of dry beans and the resulting precooked flours need less cooking time compared to whole dry beans.

Optimized formulation and processing protocol for a supplementary bean-based composite flour.

Protein-energy malnutrition is the most serious nutritional body depletion disorder among infants and young children in developing countries, attributable to inadequate energy and nutrient intake, partly due to high dietary bulk of weaning and infant foods. The gruels fed to children are typically of low nutrient and energy density due to the low flour incorporation rate required for drinking viscosity. The aim of this study was to develop a nutritious product, based on common dry beans and other grains, suitable for supplementary feeding. The optimal processing conditions for desired nutritional and sensory attributes were determined using Response Surface Methodology. For bean processing, soaking for 6, 15, or 24 h, germination for 24 or 48 h, and cooking under pressure for either 10 or 20 min were the independent variables. The processed bean flour's total polyphenol, phytic acid and protein content, the sensory acceptability of the bean-based composite porridge and its protein and starch digestibility were dependent variables. Based on product acceptability, antinutrients and protein content, as well as on protein and starch digestibility, the optimum processing conditions for the bean flour for infant and young child feeding were 24 h of soaking, 48 h of malting, and 19 min of steaming under pressure. These conditions resulted in a product with the highest desirability. The model equations developed can be used for predicting the quality of the bean flour and the bean-based composite porridge. Bean optimally processed and incorporated with grain amaranth and rice flours of a ratio of 40: 30: 30, respectively, resulted into flour with high energy, mineral, and nutrient density of the final porridge. The composite is well adaptable to preparation at rural community level. The use of these locally available grains and feasible processes could make a great contribution to nutrition security in sub-Saharan Africa and other developing countries.

Effect of heat processing on selected grain amaranth physicochemical properties.

Grain amaranth is a pseudocereal with unique agricultural, nutritional, and functional properties. This study was undertaken to determine the effect of different heat-processing methods on physicochemical and nutraceutical properties in two main grain amaranth species, of Amaranthus hypochondriacus L. and Amaranthus cruentus L. Grains were prepared by roasting and popping, milled and analyzed for changes in in vitro protein digestibility, gruel viscosity, pasting characteristics, antioxidant activity, flavonoids, and total phenolics. In vitro protein digestibility was determined using the pepsin-pancreatin enzyme system. Viscosity and pasting characteristics of samples were determined using a Brookfield Viscometer and a Rapid Visco Analyzer, respectively. The grain methanol extracts were analysed for phenolics using spectrophotometry while antioxidant activity was determined using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method. Heat treatment led to a reduction in protein digestibility, the effect being higher in popped than in roasted samples. Viscosities for roasted grain amaranth gruels were significantly higher than those obtained from raw and popped grain amaranth gruels. The results for pasting properties were consistent with the results for viscosity. In both A. hypochondriacus L. and A. cruentus L., the order of the viscosity values was roasted>raw>popped. The viscosities were also generally lower for A. cruentus L. compared to A. hypochondriacus L. Raw samples for both A. hypochondriacus L. and A. cruentus L. did not significantly differ in total phenolic content (TPC), total flavonoid content (TFC), and total antioxidant activity values. Thermal processing led to an increase in TFC and antioxidant activity. However, TPC of heat-processed samples remained unchanged. From the results, it can be concluded that heat treatment enhances antioxidant activity of grain amaranth and causes rheological changes dependent on the nature of heat treatment.

Microstructure and in vitro beta carotene bioaccessibility of heat processed orange fleshed sweet potato.

Orange fleshed sweet potato (OFSP) has been identified as a good source of beta-carotene but the beta-carotene bioaccessibility is affected by processing. In this study, the effect of traditional heat processing methods on the microstructure and in vitro bioaccessibility of beta-carotene from OFSP were investigated. Bioaccessibility was determined using simulated in vitro digestion model followed by membrane filtration to separate the micellar fraction containing bioaccessible beta-carotene. Processing led to decrease in the amount of all-trans-beta-carotene and increase in 13-cis-beta-carotene. Processed OFSP had significantly higher (P < 0.05) bioaccessible beta-carotene compared to the raw forms. Bioaccessibility varied with processing treatments in the order; raw < baked < steamed/boiled < deep fried. Light microscopy showed that the microstructure of OFSP was disrupted by the processing methods employed. The cell walls of OFSP were sloughed by the traditional heat processing methods applied. The findings show that heat processing improves bioaccessibility of beta-carotene in OFSP and this was probably due to disruption of the tissue microstructure.

Chemical and nutritional changes associated with the development of the hard-to-cook defect in common beans.

Four common bean (Phaseolus vulgaris L.) varieties, Kawanda (K)131, K132, NABE4 and NABE11, were evaluated for the relationship between development of the hard-to-cook (HTC) defect and changes in nutritional quality during 6-month storage under ambient conditions. All varieties developed the HTC defect, but the extent was found to vary with variety. Cooking time increased by 113% in K131, 95.3% in K132, 56.4% in NABE4 and 42.93% in NABE11 after 6 months. The development of the HTC defect was found to be associated with a reduction in phytic acid content (r2 = -0.802), in vitro protein digestibility (r2 = -0.872) and in vitro starch digestibility (r2 = -0.729). The susceptibility to the HTC defect during storage could be attributed to a phytic acid interaction with proteins and carbohydrates, and is also associated with small seed size. Breeding for large seed size could therefore help reduce the development of the HTC defect.