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There is an urgent need to alleviate protein deficiencies in low-income countries where cereal-based diets dominate. The objective of this study was to use the INFOGEST static digestion method and a recently established analytical workflow to determine the in vitro amino acid digestibility and protein quality of seven maize varieties grown in Malawi. Protein quality was measured using the in vitro digestible indispensable amino acid score (DIAAS). Amino acid digestibility was higher for the dehulled, low fibre, provitamin A maize flour (66%), compared to whole grain maize flours (51-61%), suggesting that the presence of fibre reduced digestibility (p < 0.05). Lysine was the limiting amino acid in all varieties, with the following DIAAS values for each variety; Provitamin A maize - 24, SC 719 - 32, Mtsikinya - 37, SC 167 - 39, Quality protein maize (QPM) - 40, Bantum - 40, SC 403 - 44. In addition to the variety of maize, protein quality was dependent on the level of processing and the agronomic practice applied with higher protein quality for the SC 403 variety in which zinc enriched fertilizer was applied. Comparing protein quality data with published in vivo data showed that DIAAS data were in closer agreement than amino acid digestibility data, which was slightly lower than published values, with mean in vitro amino acid digestibilities of 56-70% compared to a mean in vivo value of 77%. Overall, the in vitro method was able to correctly predict both the direction and magnitude of response. The INFOGEST digestion method coupled with the new analytical workflow will therefore be useful in the screening of high protein cereal crops and subsequent development of cereal-based foods with high protein quality., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Objective: This study explored the use of hydrothermally-treated soybean-fortified maize-based stiff porridge (nsima) in managing body weight losses among the farming family community in Malawi during the labour-intensive cropping (growing) season. We hypothesized that soybean-fortified maize-based nsima could prevent seasonal body weight losses in farming communities during labour-intensive seasons better than conventional 100% maize nsima., Research Methods & Procedures: A single-blind parallel dietary intervention 90-day study. During energy stress months, 42 farming households in Malawi were supplied with 15 kg of blind formulation of soybean-fortified maize flour (soybean: maize, 1:4, wt/wt) per person per month except for under-fives who were allotted half the quantity. Forty households were provided with equivalent quantities of 100% maize flour and served as control. Body weights of participants were taken at baseline and endpoint., Results: After 3 months, the experimental group registered 3.7, 4.2, 2.9, and 5.2% statistically higher body weight compared to the controls for the under-five, the 5-9-year-olds, the 10-19-year-olds, and the >20-year-olds, respectively., Conclusion: Soybean-fortified stiff porridge could feasibly be used to alleviate wasting among the resource-constraint populace in Malawi and many other parts of sub-Saharan Africa that rely on maize as a major staple., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors. Published by Elsevier Ltd.)