In situ dynamic rheological analysis of raw yam tubers: a potential phenotyping tool for quality evaluation

Most rheological analyses in yam have been done on starch gels, which requires starch extraction from the tubers. In situ rheology bypasses the need of starch extraction and relies on the original cell structure and complex matrix organization under stress or strain. Dynamic rheological properties of tuber from 16 accessions belonging to four yam species (Dioscorea rotundata, D. alata. D. bulbifera and D. dumetorum) were investigated for potential use as a medium throughput phenotyping screening tool that can indicate the quality of yam food products or their industrial potentials.Rheographs of the tubers illustrated differences in the structure of D. bulbifera compared to other yam species. High initial storage modulus (G') of yam parenchyma indicated tubers with strong and rigid structure which do not lose their structural integrity easily on heating. Dioscorea rotundata and D. alata varieties exhibited a lower temperature at which gelatinization took place (Tgel ) equivalent to the irreversible transition during starch gelatinization (75.3 and 79.8 °C) and took shorter time (867 and 958 s, respectively) to reach the G' maximum, compared to other species. The stress relaxation test showed that the higher the dry matter of the tubers, the higher the work to rupture the structure.Rheological characteristics G', loss modulus (G″), swelling capacity and Tgel showed potential as suitable quality indicators for yam products. In situ rheological characterization of yam tubers could be used as an instrumental screening tool to phenotype for quality in yam products. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry

Nutritional properties of ogi powder and sensory perception of ogi porridge made from synthetic provitamin: a maize genotype

Open Access Journal; Published online: 25 Jun 2021Provitamin-A maize (PVA) with increased carotenoid content obtained through conventional breeding techniques has been largely successful in sub-Saharan Africa. This resulted in a need to evaluate their susceptibility, retention, and nutritional content during processing into local foods. This study evaluated the chemical, carotenoid composition, and retention of PVA, the phytic acid content in ogi powder, and the sensory perception of ogi porridge produced traditionally from the three novel PVA maize genotypes (PVA SYN HGAC0 Maize 1; PVA SYN HGBC0 Maize 2; and PVA SYN HGBC1 Maize 3) and one yellow maize variety (control). Chemical composition analyses showed significant differences (p 19 years), 6.2 and 7.7%, respectively. Sensory evaluation showed that the ogi 3 porridge (Maize 3) was the most acceptable, followed by Maize 2. In conclusion, Maize 2 had the highest PVA, true retention of carotenoid, vitamin A contributions, and the second most acceptable ogi porridge with the lowest phytate content

Nutrient, Anti-Nutrient Composition and Sensory Attributes of Biscuit Made from Millet-Soy Blends

Biscuits are commonly given to children as they grow to become toddlers, and as such efforts should be made to formulate biscuits to contribute to meeting their energy and other nutrient needs.Objective: The potential of malted millet and soy in various blends for the development of toddler biscuits was investigated.Materials and methods: Malted millet and soybean seeds were processed into flour. Biscuits were formulated from the flour blends using optimisation through graphical illustration of linear programming (samples A, E and D), and compared with the traditional trial and error method (samples B and C). Nutrient and anti-nutrient content and sensory attributes of the biscuit samples were evaluated using standard methods.Results: Optimised biscuit samples had low moisture content, ranging from 4.92% to 5.42%. Protein content of the samples ranged from 11.47% - 20.39% and energy values from 422.36kcal – 473.80kcal. Sample A had highest value of β – carotene (418.40IU) and vitamin E (0.29ppm). Calcium content of the biscuit samples ranged from 994.13 – 1218.13% for all the samples, iron was 32.18 – 61.96 ppm and zinc was 28.41 – 52.08 ppm. Oxalate and trypsin inhibitor ranged from 736.50 mg/kg to 1002.40 mg/kg and 5.82mg/kg to 60.52 mg/kg, with phytate (1450.00mg/kg – 4650.00 mg/kg) and (1045.00mg/kg - 9080.00mg/kg) respectively. Sample A was also the most preferred in the sensory evaluation.Conclusion: The study showed that the biscuit made from millet-soy blends contained appreciable quantities of protein, β – carotene, vitamin E, calcium and zinc. The anti-nutritional composition of the biscuits were found to be within acceptable limits