Development of Sorghum-Wheat Buns Enriched with Giant African Land Snail Meat Powder for Improved Protein among Children Aged 3-10 Years

Abstract

Protein nutrition is important for human health because its deficiency results in public health problems such as Protein Energy Malnutrition (PEM). The situation is worse among children aged 3 to 10 years, a critical stage of physical development, where undernutrition results in irreversible effects, including delayed physical and cognitive development, as well as increased risk of infections and even mortality. Formulating cereal-based diets enriched with animal protein has been proposed as the most practical strategy to improve the nutritional quality of the diet. Buns are appropriate food vehicles because of their popularity among all age groups in rural and urban settlements due to their attractive features, including good eating quality, low cost, varied taste, and relatively long shelf-life. The main objective of this study was to formulate and develop sorghum-wheat buns enriched with snail meat powder for improved protein intake. Buns were prepared by replacing part of the sorghum-wheat flour with 5, 10, 15, 20, and 25% of SMP. Physical properties of volume, density, baking loss, yield, weight, hardness, and colour, proximate analyses including moisture, crude protein, crude fat, crude fibre, and ash, and mineral composition of iron, zinc, calcium, copper, and magnesium were determined for the buns. In vitro protein digestibility was tested using a single-enzyme assay with pepsin, whereas plate count agar and potato dextrose agar were used to enumerate the fungal and bacterial flora contaminating the buns during storage. Shelf-life determination for the buns was based on the number of days before the production of off-flavours and the presence of a fungal infestation. The protein nutritional quality of buns was evaluated on a Complete Randomized Design (CRD) with diets as treatments. Rats were randomly assigned to groups based on weight, forming the blocks, and each treatment was replicated three times within each block. Male weanling albino rats (Sprague Dawley) were used to determine the indices of PER, FER, NPRR, APD, and TPD. Bun amino acid efficiency was calculated using PDCAAS and DIAAS. Descriptive sensory and consumer acceptability with children followed RCBD that evaluated six variations of buns as treatments, which were randomized and replicated thrice with panelists as units and sessions as blocks. The adult consumer studies were based on the CRD approach. Randomized three-digit codes were assigned to the bun for blinding purposes, with sample arrangement on trays randomized for each panelist. The evaluation process was also randomized, with evaluators coming to the evaluation room at random to evaluate samples for acceptability. A descriptive panel was used to characterize the buns, and a consumer panel for acceptability using a 7-point facial scale with school children of 8-9 years old. Compositing with SMP progressively improved the buns' density, baking loss, yield, weight, and texture. Protein, fat, ash, energy, iron, zinc, calcium, magnesium, and copper were also increased. Enriching buns with between 5% and 25% SMP improved in-vitro protein digestibility. The maximum bacterial count in buns was below the International Microbiological Standard recommended units for dry and ready-to-eat foods of 103 cfu/g. Enriching with SMP also significantly (P<0.05) enhanced protein efficiency ratio from 0.21% to 2.70%, food efficiency ratio from 0.02% to 0.27%, apparent protein digestibility from 81.17% to 88.28%, and true protein digestibility from 87.48% to 95.38%. Protein digestibility corrected amino acid score, and the digestible indispensable amino acid score increased from 45% to 78% and 44% to 69%, respectively, in unenriched buns to buns enriched with 25% SMP. Principal Component Analysis (PCA) revealed 99% total variation of 23 attributes for buns scored by a descriptive sensory panel, of which 98% was due to the proportion of SMP that replaced sorghum-wheat composite flour in buns, and the remainder 1% was due to the buns’ physical appearance. Compositing sorghum-wheat buns with SMP imparts positive consumer attributes of fine crumb, sponginess, and crumby texture. Positive sensory score by school children of 8 to 9 years old for enriched buns was sustained throughout the three consumption sessions. The data obtained in this study indicate that incorporation with SMP imparted positive sensory characteristics associated with buns to the sorghum-wheat buns, and acceptance of such buns may be sustained over an extended period. Compositing sorghum-wheat flour with SMP is beneficial in formulating buns with superior protein and mineral quality in proportion to the amount of SMP added. Enriching with SMP also imparts positive physical characteristics of higher density, yield, and weight, reduces bun hardness and baking loss, and promotes better-keeping quality. In addition, enriching only at 5% with SMP significantly improved in vitro protein digestibility by 29% compared to the control. Enriching with SMP significantly promotes growth in rats, improves net protein retention, protein retention ratio, true protein digestibility, and protein digestibility corrected amino acid score of the sorghum-wheat buns to levels considered potential for use as supplementary or rehabilitation diets. Buns enriched at 25% with SMP have protein quality that promotes catch-up growth in emaciated rats, as assessed by the PER. Therefore, has the potential to alleviate PEM among children in developing countries.