Research Articles (Consumer and Food Sciences)

Permanent URI for this collectionhttp://hdl.handle.net/2263/99075

Browse

Now showing 1 - 20 of 25

Effect of coconut powder as a drying carrier medium on long-term preservation of Lactobacillus plantarum and Streptococcus thermophilus for development of starter cultures with potential application in traditionally fermented foods
(Wiley, 2024) Zulu, Nontobeko Xolisiwe; Kunadu, Angela Parry-Hanson; Kayitesi, Eugenie; Dlamini, Bhekisisa
Fermentation is of great importance to the food industry as it extends the shelf life of food while imparting desirable nutritional and sensory properties. However, the unpredictable fermentation period, inconsistency of the final product quality, and contamination with spoilage microorganisms of spontaneously fermented food remain a challenge. The aim of this study was to explore the storage stability of Lactobacillus plantarum and Streptococcus thermophilus prepared by freeze-drying using coconut powder (CCN) (25%) as a carrier medium in comparison to skim milk powder (SMP). Freeze-dried lactic acid bacteria (LAB) were evaluated for cell viability, vitality, moisture content, water activity (aw), acidification kinetics, cell morphology, and glass transition temperature (Tg). In general, LAB stored at 4°C showed better survival after 112 days than LAB stored at room temperature (RT). With cell viability, the reduction in S. thermophilus and L. plantarum counts was not significantly (p < 0 05) affected by the type of carrier media (CCN or SMP) after 112 days at 4°C. SMP supported better cell vitality (approx. 2.0) at 4°C than CCN after 112 days for L. plantarum. The moisture content and aw were within acceptable levels throughout storage on all samples. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) depicted a normal cell structure at 4°C for S. thermophilus and L. plantarum in SMP and CCN, while negative changes were observed at RT. The Tg on all samples was above 75°C, and this suggested long-term stability of the LAB strains. Overall, our findings show that CCN shows similar protection of L. plantarum and S. thermophilus strains to that of SMP during storage at 4°C. Further work is needed to confirm the fermentation performance of CCN-preserved strains.
Effect of ultrasonication on extraction yield, and the rheological and physicochemical characteristics of Mucuna sloanei gum
(Elsevier, 2025-05) Adeboye, A.S.; Amiri-Rigi, Atefeh; Emmambux, Mohammad Naushad
Mucuna sloanei flour is widely used as a thickening agent in Southern Nigerian cuisine, contributing to its texture and nutritional value. Additionally, it is gaining attention in pharmaceuticals for its health benefits, biodegradability, biocompatibility, and role in pharmaceutical formulation and controlled-release systems. However, there is a notable gap in the understanding of Mucuna gum extraction and its characterisation. This study investigated ultrasound-assisted extraction to improve gum extraction yield, as well as the physicochemical and rheological properties of M. sloanei gums. The ultrasound process improved extraction yields to 45.81 % and 47.09 % at 30 % and 60 % amplitudes, respectively, compared to 41.5 % for unsonicated extraction, reflecting enhancements of approximately 10.2 % and 13.3 % in yield while preserving or enhancing thermal properties. Thermal analysis indicated gelatinisation temperatures ranging from 92.12 to 103.40 °C, with no significant differences (p > 0.05) among gums. Thermogravimetric analysis revealed that extracted gums exhibited higher degradation onset temperatures than raw flour, indicating enhanced thermal stability which seems promising for industrial application. Furthermore, sonication reduced levels of D-xylose, d-fructose, L-(+)-arabinose, and sorbitol. Viscoelastic testing showed that the extracted gums had reduced shear-thinning behaviour and greater yield stress than the flour, suggesting their effectiveness as binders and viscosifiers. These findings underscore the potential of Mucuna sloanei gum as a commercially viable thickener in food formulations where flour is predominantly used and in the pharmaceutical industry as a natural binder, disintegrant, and controlled-release agent. The study also highlights the efficiency of ultrasound-assisted extraction as a scalable and sustainable method for gum extraction and modification.
Effect of fermentation time on the physicochemical properties and phenolic composition of malted finger millet beverages
(Wiley, 2025-03) Udeh, Henry Okwudili; Duodu, Kwaku Gyebi; Jideani, Afam Israel Obiefuna
Food security is still a significant problem, particularly in less developed nations. Orphan crops, such as finger millet (FM), are essential for meeting dietary and nutritional needs as well as providing a means of livelihood for economies with limited resources in Asia and Africa. Comparing two varieties of FM malt beverages using sorghum grain as an external reference, the research examined the impact of fermentation time on the physicochemical characteristics and phenolic composition of the FM malt beverages. The FM grains were fermented using Lactobacillus fermentum and the grain microflora. The beverages' pH decreased in a time-dependent manner throughout fermentation, and their sugar content increased accordingly. A reduction in the beverages' viscosities for both L. fermentum and the grain microflora was observed. The amount of citric acid in the beverages decreased as fermentation progressed, especially for L. fermentum. Catechin, epicatechin, and protocatechuic acid were the phenolics identified in the FM beverages. An increase in fermentation time was correlated with a decrease in the beverages' total phenolic content. At 96 h of fermentation, the beverages' DPPH, ABTS, and FRAP radical scavenging activities were significantly (p < 0.05) reduced for both L. fermentum and the grain microflora. The 24-h fermented beverages maintained higher amounts of total polyphenols and antioxidant effects. The findings indicate that FM may be utilized as a functional grain to produce nonalcoholic beverages with health benefits.
Effect of ultrasonication and temperature on hydration process and hardness of two cowpea types
(Wiley, 2024-10) Rostamirad, Sholeh; Duodu, Kwaku Gyebi; Meyer, Josua P.; Sharifpur, Mohsen; gyebi.duodu@up.ac.za
Ultrasonication deployment provides a green and non-thermal option to traditional hydrothermal treatment. This study presents the impact of ultrasonication and soaking temperatures (30 and 50 C) on the water uptake and hardness of two cowpea types under increasing soaking times (15–240 min). Moisture content and hardness of the studied samples were measured using standard test methods and instruments. An increase in soaking temperature and the use of ultrasonication enhanced water uptake and reduced hardness. Ultrasonication improved mass transfer, which enhanced the diffusion of water uptake. The samples' water uptake and softening characteristics were significantly modeled with high accuracy (R2 = 0.99) using sigmoidal and first-order kinetics equations, respectively. The impact of sonication was found to be more significant at 30 C soaking of the studied cowpeas as the soaking time increased. This work justified using ultrasonication as a green technique to enhance the softening of cowpeas.
Microwave pretreatment of presoaked Bambara groundnut seeds enhances the functionality and phenolics-related antioxidant properties of the resultant flour
(Wiley, 2024-06) Venter, Anton; Emmambux, Mohammad Naushad; Duodu, Kwaku Gyebi; gyebi.duodu@up.ac.za
This study investigated the e1ect of microwave pretreatment on cooking time of presoaked Bambara groundnut seeds, functional properties of resultant 4ours, and their phenolic composition and antioxidant properties. Microwave treatment signi6cantly decreased cooking time and resulted in decreased water solubility index (WSI) (by up to 66%) and nitrogen solubility index (NSI) (up to 81%) of the resultant 4ours, as well as a decrease in pasting viscosity and enthalpy compared to raw 4our. However, the 1200Wtreatment resulted in higher pasting viscosity, WSI, and NSI than the 900Wtreatment. .ere were di1erences in type of 4avonoids and phenolic acids between the two types of Bambara groundnut seeds, while microwave treatment caused certain increase and decrease in individual 4avonoids, such as catechin, quercetin-3-O-glucoside, and hesperidin. .e 4ours maintained good radical scavenging antioxidant activity and protected plasmid DNA from oxidative damage. Overall, the study suggests that microwave pretreatment shows potential in alleviating the hard-to-cook Bambara groundnut seeds in producing 4our with functional and antioxidant properties.
Enhancing the phenolic profile and antioxidant potency of finger millet gruels through lactic acid fermentation and incorporation
(Wiley, 2024-06) Lubaale, John; Duodu, Kwaku Gyebi
This study evaluated the effects of souring (fermenting using Lactobacillus plantarum and back-slopped inoculum and lactic acid acidification) and cooking of finger millet on phenolic content, radical scavenging properties, and inhibition of oxidative DNA damage in finger millet. Fermentation with Lactobacillus plantarum and back-slopped inoculum, and lactic acid acidification significantly increased the total phenolic content and radical scavenging properties of finger millet extracts, whereas cooking resulted in the reduction of these bioactive properties. Liquid chromatography–mass spectrometry (LC–MS) analysis confirmed the presence of phenolic acids, flavonoids, and proanthocyanidins in finger millet extracts. Both total phenolic acids and total flavonoids were elevated by fermentation (back-slopped inoculum and Lactobacillus plantarum inoculated) and lactic acid acidification but diminished by cooking. Notably, extracts from both unsoured and soured finger millet flour and gruel demonstrated protective properties against DNA damage. These findings suggest that souring enhances the phenolic content and antioxidant properties of finger millet, underscoring the potential of soured finger millet gruels for health promotion.
Gauteng’s managers’ implementation of food safety protocols and practices in their QSR environments
(African Journals Online, 2024-12) Marule, Nomzamo L.; Du Rand, Gerrie Elizabeth; Marx-Pienaar, Nadene Johanna Maria Magdalena; lesego.marule@up.ac.za
INTRODUCTION: Food safety assurance is motivated by the Food and Agriculture Organisation stating: “food safety encompasses ensuring safe food handling, and preparation when consumed according to its intended use” (FAO 1997). The importance of food safety management arises when consumers demonstrate concern and distrust that restaurants can produce safe food when compared to other industry stakeholders. Foodservice managers must promote food hygiene training aligned with safe food handling activities for the staff. The Foodstuffs, Cosmetics, and Disinfectants Act of 1972 directs the following for persons responsible on food premises: They are suitably qualified or otherwise adequately trained in the principles and practices of food safety and hygiene. Any other persons working on the food premises are suitably qualified or adequately trained in the principles and practices of food safety and hygiene. It’s a priority for food service managers to prevent the risk of reputation for their operations, to prevent legal action and closure due to employees’ poor food handling practices. Therefore, what roles do managers play in assuring that their employees follow safe food handling practices, and what would make managers effective in implementing safe food handling plans? PROBLEM: Training alone is an insufficient strategy to improve safe food handling among food service employees. Managers reported experiences that hindered the effectiveness of their roles. Managers must, however, cultivate environments where they may observe deviations in food safety and be able to efficiently address them. AIM: The study aimed to consult with managers at quick-service restaurants (QSR) to decipher the scope of implementation efforts for safe food handling in averting the risk of foodborne illnesses. METHODS: A cross-sectional, qualitative research design employed purposive sampling to engage with the managers in the QSRs. The measuring instrument was guided by the review of literature for inquiry, and aligned with general food safety concepts. A semi-formal interview schedule with open-ended questions was used. Field workers approached QSRs for data collection and made relevant general observations where possible. ANALYSIS: Foodservice managers' (n = 35) responses were transcribed. Thematic analysis was used, and data was reduced into key themes and reviewed to verify themes arising from participant responses. FINDINGS AND DISCUSSION: PERSONAL HYGIENE AND STAFF BEHAVIOUR: QSR managers used diverse but complementary approaches to enforce and maintain the staff’s behaviour related to their hygiene practices and hygiene-related behaviour. Policy included instructions not to come to work in the event of experiencing illness. Other measures included the correct wearing of PPE. QSRs were dedicated to daily deep cleaning of production and storage areas, and cleaning while working. Managers reported that employees were prompted to wash their hands in five-minute intervals. TEMPERATURE CONTROL OF FOOD: The QSR managers were asked to describe inventory policies to gauge temperature monitoring procedures. Management indicated awareness, however they did not provide evidence of this. Only two of the thirty-five managers kept records of their storage facilities. CROSS-CONTAMINATION/PATHOGEN PRESENCE: Managers reported enforcing the requirement of the separation of workspaces and colour-coded equipment when handling food. The staff were not allowed to use the store's facilities to warm up their own food as a measure to avoid cross-contamination. RAW MATERIALS/INGREDIENTS: Uniquely, visual cues were an easy go-to for evaluating ingredients. Any incoming raw materials would be examined upon delivery and returned if they were deemed to be of inferior quality (e.g. dented cans or mould on bread). Staff discarded spoilt raw materials or items that were past the expiry dates. CONCLUSIONS, RECOMMENDATIONS, AND CONTRIBUTIONS: Food safety practices and protocols were largely executed by staff, and guided by the QSR managers. The acceptance and comprehension of the importance of food safety throughout QSR requires structured cultural adoption in training, monitoring, and support from management. Knowledge and skills transferring between staff members become essential in the absence of managerial presence. Managerial absence, lacking supporting structures, and cultural adoption towards food safety compromises the required scope for implementation of safe food handling and safety protocols to avert the risks of foodborne illnesses. Instilling a safety culture through continued education, awareness campaigns, development of training programs and support mechanisms can aid managers' implementation of consistent food handling practices.
Differences in male and female consumers' perceptions of South African clothing retailers' corporate social responsibility initiatives
(African Journals Online, 2024-11) Muller, Gert Daniel; Sonnenberg, Nadine Cynthia; Donoghue, Sune; niel.muller@up.ac.za
This study explored gender differences in consumers’ perceptions of South African clothing retailers’ corporate social responsibility (CSR) initiatives based on the social, environmental and economic dimensions defined by the triple bottom line (TBL) framework. A cross-sectional survey research design with a structured online questionnaire was developed from established scales to gather reliable quantitative data that would enable exploratory factor analysis (EFA). Respondents from diverse demographic backgrounds, aged 18 and older, were recruited via time and cost-effective nonrandom sampling techniques. After splitting the data into gender-specific subsamples, EFA procedures were conducted on both datasets to compare the underlying factor structures. The results showed subtle differences in CSR perceptions: both genders valued quality services, fair pricing, and ethical stakeholder relationships, but had slightly different perceptions of social and environmental contributions. The five-factor structure for males revealed a distinct "Economic Performance" factor, while “Local Sourcing” was unique to the six-factor structure for females. The findings suggest that while both genders share some common priorities, retailers should pay attention to slight gender differences in their CSR efforts, particularly regarding social and environmental contributions. Theoretically, the study contextualises consumers’ CSR perceptions in the local clothing retail sector and provides a gendered perspective, extending current research.
Modeling and optimization of energy efficiency and product quality in staple food roasting using machine learning : a case study on cassava processing
(Elsevier, 2025-04) Mwape, Mwewa Chikonkolo; Kulig, Boris; Nurkhoeriyati, Tina; Roman, Franz; Parmar, Aditya; Emmambux, Mohammad Naushad; Hensel, Oliver
Please read abstract in the article.
Impact of added enzyme-treated bran on the techno-functional properties of puffed-extruded sorghum snack
(Elsevier, 2024-11) Antwi, Charles Kwasi; Rosa-Sibakov, Natalia; Emmambux, Mohammad Naushad
Dietary fibre intake is crucial for improving human health and reducing the prevalence of diet-related noncommunicable diseases. This study determines the effect of the enzyme (Viscozyme®L: a cocktail of cell wall degrading enzymes including arabanase, cellulase, β-glucanase, hemicellulase and xylanase) hydrolyzed fibre on the techno-functional properties of puffed-extruded sorghum snacks made from sorghum flour. Sorghum flour and sorghum flour mixed with untreated bran, water-incubated bran, and enzyme-treated bran were extruded using a twin-screw extruder. The puffed-extruded snacks from sorghum flour with 2-h enzyme-treated bran showed similar expansion ratios to snacks from sorghum flour without bran. The expansion ratios of the withoutbran snacks (2.80) and enzyme-treated bran-added snacks (2.77) were significantly (P < 0.05) higher than those made with untreated sorghum bran (1.87). A higher expansion ratio usually results in a lighter, crispier texture and a more attractive appearance of puffed-extruded snacks, which consumers often prefer. The enzyme treatment also increased the water solubility index and decreased the water absorption index compared to snacks with untreated bran. This study explores the potential of using an enzyme-treated sorghum bran to manufacture puffed-extruded snacks comparable to those made with sorghum flour.
Influence of ultrasonication during soaking on water absorption and softness characteristics in the cooking process of cowpea
(Elsevier, 2025-01) Rostamirad, Sholeh; Duodu, Kwaku Gyebi; Meyer, Josua P.; Sharifpur, Mohsen; gyebi.duodu@up.ac.za
Owing to the long duration of cooking legumes, which limits their consumption and utilization, soaking has been used to reduce cooking time, save energy consumption, and diminish their hardness. However, limited studies have reported the influence of cooking and soaking treatment along with ultrasonication on hydration, hardness, and cooking time reduction of legumes. Therefore, this study investigated the impact of cooking and soaking treatments on Dr. Saunder cowpea’s water absorption, hardness, and cooking time reduction with and without ultrasonication. Samples of Dr. Saunder’s cowpea were first soaked at 30 °C and 50 °C for 15 – 90 min (with and without ultrasonication), after which they were cooked at 100 °C and 121 °C for 15 – 120 min. The absorbed water and hardness of the tested samples under these treatments were measured. Hydration and softening behaviors were modeled from the obtained data using Ibarz-Augusto and first-order equations, respectively. Arrhenius equation was used to describe the kinetics of the hydration and softening process. Results showed that ultrasonic treatments accelerated water absorption and reduced the hardness of the samples; consequently, in a shorter time, using less energy will receive the desired hardness as the final product. The Ibartz-Augusto and first-order equations perfectively fit the sigmoidal and decaying exponential behavior of the absorbed water and hardness data with high prediction performance (R2 ≈ 1) marked by minimal error values. The deployment of ultrasonication and increased cooking temperature were observed to reduce the kinetic parameter (water absorption) and elevate the softening rates and activation energy (for hydration and softening). A synergy of the trio treatments reduced the total cooking duration from 120 min to 90 min (25 %), thus promoting the benefit of deploying ultrasonication to soften cowpeas and other seeds rapidly.
Editorial : Emerging technologies for viability enumeration of live microorganisms
(Frontiers Media, 2025-01-16) Shehata, Hanan R.; Pane, Marco; Buys, E.M. (Elna Maria); Koshy, Binu; Vegge, Christina S.; Schoeni, Jean L.
The live microorganism industry is rapidly growing, producing probiotics and live biotherapeutic products (LBPs) designed to deliver health benefits. Ensuring these products contain viable, strain-specific microorganisms at effective levels is essential, but accurately measuring viability and potency remains challenging.
Soy protein–xanthan gum noncovalent interactions : exploring functional outcomes and food applications
(American Chemical Society, 2025-01) Muhoza, Bertrand; Harimana, Yves; Kayitesi, Eugenie; Uriho, Angelo
Soy proteins stand out as the primary choice among plant-based proteins in commercial use due to their functional characteristics, wide availability, cost-effectiveness, and eco-friendly nature. However, their inherent functional constraints may limit the technological applicability of commercially available soy proteins. The interaction between soy protein and charged polysaccharides through noncovalent bonds provides a straightforward and scalable method to enhance functional properties and expand the range of applications. With its anionic properties, xanthan gum possesses distinct structural and conformational attributes that effectively improve plant proteins’ properties, across various conditions. This review explores the realm of noncovalent interactions between soy protein and xanthan gum, elucidating their mechanisms and the resulting complex properties. Additionally, the utilization of these complexes in diverse applications, including encapsulating bioactive compounds, producing low-fat foods, creating meat alternatives, formulating starch-based products, and enhancing bakery and beverage formulations, is examined. The review also discusses the challenges associated with producing and applying soy protein–xanthan gum complexes while outlining the prospects. Emphasis is placed on the critical need to scale up the production and utilization of these complexes in developing calorie-conscious and elderly friendly food products.
Effect of extrusion cooking in combination with food-to-food fortification on the mineral bioaccessibility of African-type pearl millet-based porridge
(Elsevier, 2024-03) Famuyide, Oluyimika Y.; Lubaale, John; Ndiaye, Cheikh; Duodu, Kwaku Gyebi; Taylor, John R.N.; john.taylor@up.ac.za
Mineral deficiencies, especially iron and zinc, are still prevalent in urban as well as rural communities among women and children across Africa, including the Sahel. Here, effects of extrusion cooking in combination with food-to-food fortification (FtFF) with plant foods rich in minerals (moringa leaf powder) and their bioavailability enhancers, organic acids (baobab fruit) and β-carotene (carrots, mango, papaya) and additionally micronutrient premix fortification on iron, zinc and other mineral bioaccessibilities in wholegrain pearl millet-based porridges in comparison to their conventionally wet-cooked equivalents were investigated. Percentage bioaccessible iron in extrusion-cooked porridges FtFF with moringa+baobab+carrots+mango, baobab+carrots+papaya and together with micronutrient premix was generally similar to their conventionally cooked FtFF-porridge equivalents. However, the amount of bioaccessible iron in the extrusion-cooked FtFF-porridges was some three times higher. Iron contamination through solubilization from the extruder parts was responsible. Percentage and amount of bioaccessible zinc of the extrusion-cooked FtFF-porridges was substantially increased. This is likely due to phytate degradation during extrusion cooking, thereby reducing the phytate's mineral-chelating effects. Concerning calcium and magnesium, there was no positive effect of extrusion cooking on their bioaccessibility when compared to conventional cooking. However, FtFF substantially increased the amount of bioaccessible calcium and magnesium in the conventionally- and extrusion-cooked FtFF-porridges because of their high contents in moringa and baobab. Consumption of extrusion-cooked ready-to-eat FtFF-porridges, especially when additionally conventionally fortified, is promising to significantly improve bioaccessible iron and zinc in the diet of at-risk African populations, particularly in urban communities.
Extruded wholegrain sorghum porridges fortified with baobab fruit and moringa leaves display bioactive phenolics-related health-promoting properties
(Elsevier, 2024-07-20) Lubaale, John; Serem, June Cheptoo; Bester, Megan Jean; Emmambux, Mohammad Naushad; Duodu, Kwaku Gyebi; gyebi.duodu@up.ac.za
BACKGROUND AND OBJECTIVES : Food-to-food fortification (FtFF) is gaining traction as a strategy to enhance nutritional value of cereal-based foods. Sorghum, a major food crop for millions in the semi-arid tropics lends itself to such FtFF efforts. Such food-to-food fortified (FtF fortified) foods also contain bioactive phenolics with healthpromoting properties in relation to potential protection against diet-related non-communicable diseases (NCDs) whose prevalence is increasing in sub-Saharan Africa. In this study, the effects of extrusion cooking of sorghum-based porridges FtF fortified with baobab fruit powder and moringa leaf powder on antioxidant, antiinflammatory, antidiabetic and anti-lipogenic properties were determined. FINDINGS : FtFF porridges showed higher phenolic content (phenolic acids and their esters, flavonoids and their glycosides) and greater radical scavenging properties and reduction in advanced glycation end products (AGEs) compared to unfortified porridges. Extruded instant porridges had lower phenolic content, radical scavenging properties and showed less reduction in AGEs compared to conventionally wet-cooked porridges. All porridges exerted antioxidant effects in Caco-2 cells and FtFF inhibited nitric oxide (NO) formation in RAW 264.7 cells. Extracts from all porridge samples exhibited prevention and reduction of adipocyte formation in 3 T3-L1 cells, indicating anti-lipogenic effects. CONCLUSION : FtFF (with moringa and baobab) and extrusion cooking can be used to produce instant porridges from wholegrain sorghums with targeted health-promoting properties to address rising non-communicable diseases in sub-Saharan Africa. SIGNIFICANCE AND NOVELTY : This study highlights the potential of FtFF with tropical plant foodstuffs to improve health-promoting properties of cereal wholegrain-based starchy staple foods.
Potato ice cream and beyond
(Plaas Media, 2024-11) Muller, Carmen; Fisher, Hendrik Johannes (Hennie); Potgieter, Lerika; hennie.fisher@up.ac.za
When it comes to culinary versatility, few ingredients can compete with the humble spud. This starchy superstar has outgrown its traditional status of being only a side dish. Nowadays potatoes are celebrated as culinary chameleons that can be transformed into a multitude of dishes that suit every palate and dietary preference.
Urging bioactive peptide exploration in African fermented legumes : insights from microbial proteolysis to gastrointestinal stability
(Springer nature, 2024-12) Moyo, Siphosanele Mafa; Famuyide, Oluyimika Y.; Kayitesi, Eugenie; eugenie.kayitesi@up.ac.za
Microorganisms such as Bacillus spp., Propionibacterium spp., Lactobacillus spp., Citrobacter spp., Enterobacter spp., Klebsiella spp, and Aspergillus spp. play vital roles in fermenting macromolecules present in African legumes, resulting in beneficial derivatives with diverse bioactivities advantageous to human health. While fermentation of legumes is a common practice in Africa, yielding nutritious products rich in phenolic compounds, the specific contribution of peptides generated during this process to the health-promoting qualities of legumes remains underexplored. This review aims to demonstrate the possibility of the occurrence of bioactive peptides in fermented African legume products by investigating the intricate processes underlying microbial conversion of proteins into peptides and explaining the structure–activity relationship governing their bioactivity. The review also evaluates the stability of bioactive peptides during digestion in the human gastrointestinal tract, shedding light on their potential health benefits. African fermented legume products could be utilized in various food systems such as condiments, meat binders and components of high-protein snacks, as sources of bioactive compounds in the production of functional foods and nutraceuticals. In summary, this comprehensive examination not only summarizes our understanding of the health-promoting qualities of fermented African legume products but also underscores their potential as sustainable food sources for commercial utilization in diverse food industries.
Dietary intake and growth of HIV exposed and unexposed 6-12 months old infants in South Africa
(Wiley, 2025-01) Tshiambara, Phumudzo; Hoffman, Marinel; Legodi, Heather; Balakrishna, Yusentha; Feucht, Ute Dagmar; phumudzo.mamphwe@up.ac.za
Factors affecting the growth of HIV‐exposed‐uninfected (HEU) children are multi‐factorial, with limited information available on the dietary intake from 6 months. This study compared the dietary intake, micronutrient composition of breastmilk, and growth of HEU and HIV‐unexposed‐uninfected (HUU) infants aged 6 and 12 months in an urban setting. A repeated cross‐sectional study used structured questionnaires to collect socio‐demographic, dietary intake, food group data, and anthropometric measurements in the Siyakhula study. The HEU (48%) and HUU (52%) infants were included (total n = 181). At 6 months, HEU infants had lower weight‐for‐age z‐scores (WAZ) (−0.6 ± 1.1 vs. 0.1 ± 1.2; p < 0.001), length‐for‐age z‐scores (−0.8 ± 1.4 vs. −0.1 ± 1.2; p < 0.001), and mid‐upper‐arm circumference‐forage z‐scores (MUACAZ) (0.5 ± 1.1 vs. 1.0 ± 0.9; p < 0.001) than HUU infants. At 12 months, HEU infants had lower WAZ, MUACAZ, and weight‐for‐length z‐scores compared to HUU infants (p < 0.05). Stunting was found at 6 (15%) and 12 (12%) months in HEU infants. The micronutrient composition of breastmilk fed to both groups was similar. Breastfeeding rates were lower in HEU than in HUU infants at 6 (49% vs. 64%; p = 0.005) and 12 (24% vs. 46%; p = 0.002) months. Less than 3% of HEU and HUU infants achieved minimal dietary diversity scores at 12 months. Dietary intake of fat was similar in all breastfed infants, but iron and vitamin B12 were higher in non‐breastfed HEU infants at 12 months. HEU infants had lower breastfeeding rates than HUU infants. A lack of dietary diversity was found in all infants. Nutrition education and counselling in the complementary feeding phase are essential for optimal growth.
Influence of protein in low paste viscosities of Bambara groundnut flours from heat-treated Bambara groundnut seeds
(Elsevier, 2024-11) Mukwevho, Peter; Emmambux, Mohammad Naushad; peter.mukwevho@up.ac.za
Heat treatment of Bambara groundnut seeds has been reported to cause low paste viscosities in resulting flours. Structural changes in Bambara groundnut protein, due to heat treatment, causes the protein to encapsulate starch, making it unavailable to paste causing low paste viscosities. In this study, trypsin was used to hydrolyze proteins in the flour and the microstructure analysis confirmed the disappearance of aggregates. Flour microstructure analysis confirmed hydrolysis of protein from previously aggregated status and showed liberated individual starch granules. Following the treatment of flours by trypsin, Confocal laser scanning microscopy did not show a protein signal. Hydrolysing Bambara groundnut proteins significantly increased the flour paste viscosities (P < 0.05). The final viscosities for flours from 20 % moisture-conditioned and infrared heat-treated seeds for 5 min were 733.9 mPa s before protein hydrolysis and 2081.71 mPa s after protein hydrolysis. The gelatinization temperature (81 ◦C) did not show a significant change following protein hydrolysis. Sodium dodecyl-sulphate polyacrylamide gel electrophoresis band intensity increased indicative of disulfide bonding and protein polymerisation when microwave and infrared heat treatment were combined. There were changes in Bambara groundnut protein secondary structures such as an increase of 57 % in β-sheet along with a 60 % reduction in the α-helix as shown by the Fourier-transform infrared spectroscopy. The changes in secondary structure of Bambara groundnut protein were caused by microwave and infrared heating. Heat treatment of Bambara groundnut seeds is partly responsible for the reduction in paste viscosities of their flours.
Development, validation, and application of a South African dietary polyphenol data quality assessment tool
(Elsevier, 2024-11) Jumat, Malory; Duodu, Kwaku Gyebi; Van Graan, Averalda
There is a wealth of South African scientific literature studying and reporting on dietary polyphenols in research articles and academic literature. The evaluation of data quality is critical to ensure polyphenol data compiled from various scientific journals and academic texts are acceptable in terms of compilation standards. This study aimed to develop, validate, and apply a country specific South African dietary polyphenol data quality assessment tool (SADPDQAT). The evaluation tool considered nine evaluation categories with a maximum score of 5. For each literature source assessed, a quality score and confidence code was assigned. Validation analysis revealed generally consistent results between raters with an average percentage agreement of 65 %, no scores falling outside of Bland-Altman limits of agreement and a moderate internal consistency α = 0.533 which was improved to 0.616. Applying the tool to 383 scientific studies showed that most literature obtained a quality score between 70 and 79 % resulting in a confidence code of “B” (n = 166, 43 %) and a score between 60 and 69 % resulting in a confidence code of “C” (n = 125, 33 %). The SADPDQAT can be used to evaluate a variety of dietary polyphenol containing literature and aids in setting priorities for further research in this area.

Browse

Recent Submissions