Changes in physico-chemical characteristics and volatile flavour components of different yoghurt products made from soy, peanuts and cow milk

Milk blends from legumes are potential nutritional substitutes in cultures where cow milk is used for yoghurt production. Peanut and soy based products have been considered to have poor sensory characteristics due to the beany and off-flavours they generate in food products that contain them. The high polyunsaturated fatty acid content of legumes makes these products susceptible to lipid oxidation leading to rancidity and development of off-flavours. Acceptability ratings of these products have been significantly lower than the traditional dairy products. Nonetheless, food scientists are still faced with the challenge of formulating foods that are appealing and acceptable to consumers, but still contain significant amounts of these oilseed proteins for their health benefits. The development of a storage stable yoghurt product from these vegetable seeds has the potential to increase utilization and market for peanut and soy beans. The study investigated the keeping quality of Soy-peanut-cow milk yoghurt (SPCY), Defatted peanut-soy milk yoghurt (DPSY) and Cow milk yoghurt (CMY) refrigerated at 5°C over a period of 21 days during storage. Volatile flavor compounds in the different yoghurt samples were determined by static head space technique using Gas Chromatography-Mass Spectrometer (GC-MS). Titratable acidity increased in all samples after one week of storage but was highest in CMY (1.2% - 2.60%) followed by DPSY (0.57% - 0.89%). SPCY had the least titratable acidity value (0.23% - 0.44%). CMY and DPSY were more susceptible to syneresis. Free fatty acid (FFA) and peroxide value (PV) were high in the full fat product compared to defatted product and cow milk yoghurt. Flavour analysis using GC-MS identified aldehydes, alcohols, organic acids and furans as the volatile flavour components in the yoghurts studied. The defatted vegetable milk yoghurt (DPSY) had better storage keeping qualities than the whole fat vegetable milk yoghurt (SPCY) and the control (CMY). Defatting of oilseeds prior to use in food formulations can enhance the storage stability of the products. Utilization of less expensive and available indigenous crops such as soy beans and peanut in yoghurt production will help reduce the cost of the product in some developing countries.Key words: Vegetable milk yoghurt, storage characteristics, volatile flavour compound

Anaemia prevalence and nutrient intake among women in peri-urban settlements in Accra, Ghana

Anaemia among women is a major public health concern globally. In developing countries, nutritional anaemia may be due to poor bioavailability of dietary iron, haemoglobinopathies, or intestinal parasites. The study objectives were to determine the prevalence of anaemia and current nutrient intakes essential to erythropoiesis among women of reproductive age (WRA) in peri-urban settlements in the Ga-East Municipality, Accra, Ghana. This cross-sectional study assessed the nutrient intake, sickling and haemoglobin levels of 134 women aged 15-49 years enrolled in a peanut-based field trial at baseline. A pretested semi-quantitative food frequency questionnaire was used to assess energy and nutrient intake using the Food Processor (ESHA) software. Whole blood was used to determine full blood count using the haematology automated analyser. Sickling was determined by blood staining. Anaemia was classified based on recommended cut-offs. Chi-square analysis was used as a test of independence between anaemia and age groups. Linear regression was used to determine predictors of haemoglobin concentration. The mean age of the women was 29 ± 8 years. The mean total caloric intake was 2315 ± 915 kcal, whilst protein and fat intakes were 67 ± 27g and 68± 30g, respectively. Almost three-quarters of the women met the recommended dietary allowance (RDA) for iron and vitamin C. However, only a third met the RDA for fat, and about two-thirds met their needs for energy and protein. None of the women met the RDA for folate which is integral for haem formation. Also 17% (23/134) of the women were sickle cell anaemia positive. Mean haemoglobin concentration was 12.1 ± 1.8 g/dL. Mild, moderate and severe anaemia due to iron deficiency was present in 35.8%, 6.7% and 1.5%, of the women respectively. All categories of anaemia was present in 44% of the women. Anaemia, prevalence increased during the early stages of the reproductive age (15-29 years) and declined towards the end of the reproductive age period (40-49 years). An increase in age of one year was significantly associated with a 0.056 g/dL rise in haemoglobin level (p=0.014). Anaemia due to iron deficiency exists as a public health problem among women in peri-urban settlements in the Ga-East Municipality, Accra, Ghana. Dietary diversity to include green leafy vegetables which are rich in folate and pro-vitamin A may reduce the current level of prevalence.Key words: Anaemia, Nutrients, Peri-urban, Women, RDA, sickling test, Food Processor softwar

Consumer Perceptions, Knowledge and Preferences for Aromatic Rice Types in Ghana

Abstract: Even though rice forms a major part of the Ghanaian diet, locally produced rice is not patronized as it should. A survey of 390 rice consumers was conducted in Accra, Ghana to ascertain consumer perceptions, knowledge and preferences for aromatic rice as a basis for quality improvement of local rice. Results showed that most consumers (94.9%) were more familiar with imported rice and this was reflected in their patronage patterns. The reasons why consumers did not patronize locally cultivated rice are poor post harvest handling, non-availability, and the generally perceived poor quality. The few (29%) who consume local rice do so out of the perception that it is inexpensive and has better nutritional quality. Both cooked and raw attributes of rice influence consumer preference. Whilst the appearance of raw rice (Friedman rank mean = 2.86) was critical to consumers' choice, taste and aroma determined consumer preference for cooked rice; being ranked 4.96 and 4.46 respectively. [Nature and Science 2010;8(12):12-19] (ISSN: 1545-0740)

Characterization of physicochemical and microbial quality, functional properties, and shelf stability of fermented tigernut-based probiotic beverages

Tigernuts and millet are indigenous underutilized crops in West Africa that have versatile applications in food processing. These crops are rich in fermentable carbohydrates, resistant starch, fiber, and micronutrients, making them ideal candidates for pre- and probiotic (synbiotic) foods. This study utilized whole tigernuts in a dairy–millet-based fermented beverage called brukina, turned it to a synbiotic, and assessed the functional and physicochemical profiles, microbial quality, and shelf stability of the beverage. The tigernut–millet agglomerate was prepared by incorporating cellulose-hydrolyzed tigernut fibrous (TNF) cake and non-hydrolyzed TNF (10% and 15%, respectively) into millet and allowing to ferment for 12 and 24 h. Brukina produced from composite tigernut milk: dairy in a ratio of 40%:60% was inoculated with the probiotic Lacticaseibacillus casei after pasteurization. The beverage was analyzed for physicochemical, proximate, and functional properties and microbiological stability at 5°C and 25°C. The obtained data were subjected to analysis of variance (ANOVA) in Minitab version 17 using a general linear model to determine the variability, interactions, and significance of the measured product characteristics. The agglomerate water absorption capacity (l/g) ranged from 0.70 ± 0.17 to 0.89 ± 0.17, bulk density (g/l) from 0.55 ± 0.04 to 0.63 ± 0.00, and swell index (%) from 1.62 ± 0.08 to 1.80 ± 0.06. The agglomerate prepared from dough and fermented for 12 h had excellent functional characteristics and was selected for synbiotic brukina production. Moisture content of the product decreased (p < 0.001) with tigernut incorporation ranging from 78.85% to 70.45%, while sodium, phosphorus, protein, total carbohydrate, and crude fiber increased with tigernut incorporation (p < 0.05). Synbiotic brukina supported the growth of L. casei attaining 11 log CFU/mL with a corresponding increase in lactic acid production and was microbiologically safe at 5°C and 25°C for 5 days compared to unpasteurized and uninoculated probiotic control (p < 0.05). The addition of whole tigernuts and L. casei to brukina enhanced its nutritional content with a shelf stability of 3 days

The fermentation characteristics of single and mixed yeast cultures during pito wort fermentation

Abstract Pito is an alcoholic beverage obtained through yeast fermentation of the wort extracted from sorghum malt. The production methods are largely artisanal and the product quality varies from batch to batch even for the same brewer. The use of starter culture is a plausible approach to minimizing the variability in product quality. This work compared the fermentation profile of single yeast and mixed yeast cultures in sorghum wort fermentation during pito production. A 2 x 3 factorial design was used to study the quality characteristics of wort pitched with single and mixed Culture yeast strains during 24, 48 and 72 hours alcoholic fermentation. The physicochemical properties, microbial load and sensory characteristics of samples were determined. Fermentation time had significant effects (p<0.05) on the pito characteristics. Pito color (of 12.5 and 16.5 EBC units) was different for single and mixed cultures respectively. Panelists perceived the colours of pito obtained from single yeast culture fermentation to be different from that obtained from mixed culture fermentation. Volatile aroma compounds identified during the fermentation period included esters (4), aldehydes (3), organic acids (2), alcohols (3) and a diacetyl. Both single and mixed cultures showed similar characteristics during wort fermentation

DataSheet1_Characterization of physicochemical and microbial quality, functional properties, and shelf stability of fermented tigernut-based probiotic beverages.pdf

Tigernuts and millet are indigenous underutilized crops in West Africa that have versatile applications in food processing. These crops are rich in fermentable carbohydrates, resistant starch, fiber, and micronutrients, making them ideal candidates for pre- and probiotic (synbiotic) foods. This study utilized whole tigernuts in a dairy–millet-based fermented beverage called brukina, turned it to a synbiotic, and assessed the functional and physicochemical profiles, microbial quality, and shelf stability of the beverage. The tigernut–millet agglomerate was prepared by incorporating cellulose-hydrolyzed tigernut fibrous (TNF) cake and non-hydrolyzed TNF (10% and 15%, respectively) into millet and allowing to ferment for 12 and 24 h. Brukina produced from composite tigernut milk: dairy in a ratio of 40%:60% was inoculated with the probiotic Lacticaseibacillus casei after pasteurization. The beverage was analyzed for physicochemical, proximate, and functional properties and microbiological stability at 5°C and 25°C. The obtained data were subjected to analysis of variance (ANOVA) in Minitab version 17 using a general linear model to determine the variability, interactions, and significance of the measured product characteristics. The agglomerate water absorption capacity (l/g) ranged from 0.70 ± 0.17 to 0.89 ± 0.17, bulk density (g/l) from 0.55 ± 0.04 to 0.63 ± 0.00, and swell index (%) from 1.62 ± 0.08 to 1.80 ± 0.06. The agglomerate prepared from dough and fermented for 12 h had excellent functional characteristics and was selected for synbiotic brukina production. Moisture content of the product decreased (p < 0.001) with tigernut incorporation ranging from 78.85% to 70.45%, while sodium, phosphorus, protein, total carbohydrate, and crude fiber increased with tigernut incorporation (p < 0.05). Synbiotic brukina supported the growth of L. casei attaining 11 log CFU/mL with a corresponding increase in lactic acid production and was microbiologically safe at 5°C and 25°C for 5 days compared to unpasteurized and uninoculated probiotic control (p < 0.05). The addition of whole tigernuts and L. casei to brukina enhanced its nutritional content with a shelf stability of 3 days.</p

Soybean-Enriched Snacks Based on African Rice

Snacks were produced by extruding blends of partially-defatted soybean flour with flours from milled or parboiled African-grown rice. The interplay between composition and processing in producing snacks with a satisfactory sensory profile was addressed by e-sensing, and by molecular and rheological approaches. Soybean proteins play a main role in defining the properties of the protein network in the products. At the same content in soybean flour, use of parboiled rice flour increases the snack’s hardness. Electronic nose and electronic tongue discriminated samples containing a higher amount of soybean flour from those with a lower soybean flour content