Masters Degrees (Sustainable Food Systems and Development)

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Browsing Masters Degrees (Sustainable Food Systems and Development) by Author "Colbert, Taylon Anthony"

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    Acceptance, attitudes and nutritional content of novel nixtamalized maize products developed for the South African consumer
    (University of the Free State, 2023) Colbert, Taylon Anthony; Du Toit, Alba; Bothma, Carina; van Niekerk, Johan; Swanepoel, Jan Willem
    South Africa is well-known for its good quality maize that serves as a staple crop for over 80% of the country’s population. Additionally, South Africa is also Africa’s top maize producer. However, maize provides an unbalanced supply of essential nutrients, such as the essential amino acids lysine and tryptophan. Moreover, the water-soluble vitamin B₃ is biologically unavailable to humans. Therefore, long-term consumption of maize-based diets, deficient in these nutrients, can result in pellagra, a disease manifested by the characteristic symptom dermatitis, on sun-exposed skin. The process of nixtamalization improves the nutritional, textural and sensory quality, and the physicochemical properties of maize products. Nixtamalization is the traditional process of preparing maize in Mexico. It involves cooking and soaking maize kernels in an alkaline solution, typically calcium hydroxide or slaked lime. The process allows bound nutrients to be more readily available for absorption, improves flavour and texture, as well as digestion. This study was divided into three essential phases: (I) the development of consumer-acceptable novel nixtamalized maize products; (II) the determination of consumer attitudes, knowledge and awareness towards nixtamalization and nixtamalized maize products, through the administration of a questionnaire; and (III) the analysis of the nutritional content of a novel consumer accepted nixtamalized maize product. The first phase aimed to explore South African consumers' acceptance of nixtamalization and novel nixtamalized maize products. Three nixtamalized maize products were developed: a vegetarian patty; a vegetarian nugget; and a maize chip. To evaluate the consumers' sensory acceptance of various attributes, including taste, aroma, texture, and appearance, the study employed the Just-About-Right (JAR) scales and a 9-point hedonic scale. Among the three products evaluated, the maize chip received the most acceptable JAR results, although improvements were required for its appearance attribute. Furthermore, correlation and penalty analysis revealed that appearance and taste played significant roles in the acceptance of nixtamalized maize products, among South African consumers. Consequently, the chips were flavoured with seasonings to improve taste and appearance, with different flavours, such as chutney and tomato. Notably, the chutney-flavoured maize chip achieved an acceptance rate of >70.0% for all four attributes, rendering it “just-about-right”. The study's second phase involved determining consumers’ attitudes toward nixtamalization and nixtamalized maize products. The data was collected online, using an Evasys© questionnaire, which was anonymously completed by respondents, during the sensory tasting of the maize chips. Quantitative analysis concluded that most respondents were open to nixtamalization as a new processing technique and to newly developed maize products produced, through nixtamalization. Specifically, respondents indicated that the safety aspect of nixtamalization played a crucial role in their willingness to consume nixtamalized maize, in the future. Moreover, the results indicated that the respondents were willing to incorporate nixtamalized products into their future consumption, and recommend them to friends and family. After achieving consumer acceptance, the third phase of the study focused on conducting nutritional analysis of the novel nixtamalized maize chip. The analysis revealed several noteworthy findings. The chips exhibited a high energy content of 2303 kJ/100 g and protein content of 6.64 g/100 g. Compared to two commercial chips, the nixtamalized maize chip displayed a higher insoluble fibre content of 15.87 g/100 g of NDF and 1.32 g/100 g of ADF. Additionally, the sodium content of the maize chip (706.67 mg/100 g), fell within the permissible limit set out by South African salt legislation (<800 mg/100 g), for savoury snack foods. Moreover, the chips demonstrated favourable potassium, calcium, phosphorus, and magnesium levels. The higher fat content of 23.72 g/100 g in the chips was attributed to the deep-frying process, used during preparation.