Browsing by Author "Ngobese, Nomali Ziphorah."

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Effects of some of the procedural steps of cyropreservation on cryo-recalcitrant zygotic embryos of three amaryllid species producing desiccation-sensitive seeds.
(2013) Ngobese, Nomali Ziphorah.; Berjak, Patricia.; Pammenter, Norman William.
Cryopreservation is the most promising method for the long-term conservation of germplasm of plants producing desiccation-sensitive seeds. While such seeds are generally termed recalcitrant in the context of conventional storage practices, the term ‘cryo-recalcitrant’ is used for germplasm which is not readily amenable to cryopreservation. Cryo procedures usually involve a sequential combination of steps which must be optimised to limit the stresses experienced by specimens, thus promoting their survival. The present contribution reports on the effects of some of the steps involved in cryopreservation on the survival of the embryos of the amaryllids, Ammocharis coranica, Brunsvigia grandiflora and Haemanthus albiflos, with the ultimate aim of developing a protocol(s) for the successful cryopreservation of the germplasm of these species. The main foci of the investigations were the effects of rapid (flash) drying, the use of the cryoprotectant additives, glycerol (5 & 10%) and DMSO (0.1 & 0.25%), and employment of different cooling rates on the zygotic embryos of the selected species, which are known to be recalcitrant as well as being cryo-recalcitrant. Furthermore, this study reports on attempts at improving the rapidity of dehydration during flash drying by applying a vacuum, and also of providing cathodic protection (via highly reducing cathodic water and/or direct exposure to a static {negatively-charged} cathodic field during flash drying) to the explants at various stages in the protocol. These techniques were employed in attempts to ameliorate the adverse effects of reactive oxygen species associated with stresses imposed by the procedures during the cryopreservation process. The embryos of Ammocharis coranica, Brunsvigia grandiflora and Haemanthus albiflos were initially at water contents (WCs, dry mass basis) of 3.28±0.52, 2.55±0.22, 4.48±0.92 g g-1, respectively, after harvest. These embryos proved to be tolerant to moderately rapid water loss in the short term, with >60% retaining germinability at water contents ≥0.5 g g-1. The results from this study confirmed that dehydration to water contents below 0.5 g g-1 (dry mass basis) compromised survival, and that this effect was exacerbated if the embryos were cryoprotected prior to drying. Interestingly, the rate of water loss in embryos of these species differed, with A. coranica and H. albiflos drying at a (comparably) much slower rate than those of B. grandiflora. Subsequent rapid cooling yielded promising results when compared with slow cooling, as 30% of glycerol cryoprotected, rapidly cooled A. coranica embryos that had been flash-dried to 0.36±0.10 g g-1 generated normal seedlings. It was clear, however, that the effects of these procedures were exacerbated when all the steps of the cryo procedure were applied sequentially. However, the work also showed that these adverse effects may be ameliorated if each step of the cryopreservation protocol is optimised on a species-specific basis, thus promoting the chances of survival after cryopreservation and facilitating subsequent seedling establishment. This was evident in the 30% germination obtained when embryos of A. coranica, which had been cryoprotected with glycerol prior to flash drying before exposure to rapid cooling, while those that had not been cryoprotected or were cryoprotected with DMSO before drying did not survive. The incorporation of cathodic protection during flash drying appeared promising as it promoted the survival of 10% of H. albiflos embryos dehydrated to WCs between 0.37 and 0.26 g g-1 (whereas no survival was achieved without the inclusion of this step), and 70% of A. coranica embryos that were dehydrated to 0.35±0.21. In addition, the reduction of the explant size, from a whole 6 mm embryo to a 3-4 mm excised axis, promoted survival by up to 30% for A. coranica and H. albiflos, even at higher WCs. However, survival in these cases was based on observations of abnormal development, i.e. the development of roots or shoots, or calli. No surviving embryos were obtained from B. grandiflora after cooling, regardless of the preconditioning treatment or rate of cooling, and this was accredited to the greater degree of sensitivity of these embryos to the cryo procedures than those of the other two species. The use of cathodic water to re-hydrate explants after dehydration and of applying a vacuum during flash drying did not result in any observable benefits, and require further investigation for optimisation. The very limited success towards establishing a cryopreservation protocol for the species investigated in this study reinforces the difficulties associated with the cryopreservation of recalcitrant germplasm, which informs the cryo-recalcitrance of some explants. However, the results obtained have helped to identify a number of intervention points that could be used to minimise the damage incurred during the various procedural steps involved in cryopreservation.
Indigenising instant noodles: an interface of traditional amaranthus leaves and wheat for improved food and nutrition security.
(2019) Qumbisa, Nothando Delight.; Kolanisi, Unathi.; Siwela, Muthulisi.; Ngobese, Nomali Ziphorah.
Instant noodles are becoming the new global staple and breakfast food due to their versatility and convenience. For centuries, instant noodles were a staple food only in East Asian countries; however, their consumption has increasingly grown globally. According to research findings, instant noodles are preferred because of their taste, extended shelf-life, affordability as well as convenience, which suits the busy lifestyle of the student and working population. There is a concern though, of the adequacy of nutrients obtained from instant noodles especially when consumed as a single food item. Researchers are therefore exploring the potential supplementation of noodles to make them a composite food to improve their nutritional value. Food supplementation using vegetable-based nutrients is steadily gaining momentum. It is a growing modern trend in response to consumer demands and health concerns. However, the use of traditional green leafy vegetables, which have high nutritional value, such as Amaranthus has been limited in South Africa. The aim of this study therefore was to investigate the nutritional quality, consumer acceptability and physical quality of Amaranthus-supplemented noodles among students at the University of Zululand (UniZulu), KwaDlangezwa Campus in South Africa. This was done to indigenize the product in an effort to mitigate food and nutrition insecurity challenges. Methodology A quantitative research approach was followed in conducting the study. Descriptive and experimental designs were applied. A survey was conducted with 100 students to investigate the consumption of noodles and utilisation of Amaranthus among students using a self-administered questionnaire. Stratified purposive quota sampling was used to recruit participants for the survey investigating the utilisation of noodles. Amaranthus-supplemented noodles were developed by substituting wheat flour at 1, 2 and 3% (w/w) with Amaranthus leaf powder in a standard noodle recipe. The noodle samples were analysed for nutritional composition using AOAC methods. The physical quality of cooked noodle samples was assessed in terms of colour (CIELAB system) and texture (using texture analyser), and consumer acceptability was assessed by 60 untrained panellists. Results The survey results indicated that the majority (93%) of the university students consumed instant noodles. The students consumed an average of two packets per week, as well as eight packets (per person) per month. About 58% of the students ate noodles as their main subsistence food without other food items to improve nutrient intake. About 14% of the students ate noodles with other food items such as mayonnaise, sauces, cheese, bread, with 5% of them combining noodles with pieces of chicken (2%), fish (1%) and boerewors/sausage (2%). Approximately 65% of the students mentioned two dominant attributes that influenced them to consume noodles: convenience (shelf-stable food) and time-saving (quick to prepare). The majority of the students (76%) knew of Amaranthus as a vegetable. Amongst the 76% that had knowledge of Amaranthus, 71% were consumers or had at least consumed Amaranthus once in their lifetime. The majority (92%) of the students consumed Amaranthus in the form of a leafy vegetable. Results of nutritional analysis showed that the protein content of Amaranthus leaf powder (ALP)-supplemented noodles was similar to that of the control (conventional instant noodles) and remained above the recommended percentage content (8%) for all the samples. Instant noodles supplemented with ALP had an improved fibre content, as well as ash content, suggesting that Amaranthus can be used to improve nutritional value. With regard to mineral composition, significant increases were observed for manganese, calcium and copper upon incorporation of ALP in the noodles. The antioxidant activity increased. Texture analyses results showed that ALP-supplemented noodles were softer (240 g cutting force) than the control, i.e. noodles without ALP (600 g force). The increase in ALP concentration had a significant effect on colour as shown by diminishing of yellowness of noodles while progressively shifting towards greenness. Sensory evaluation results revealed that the addition of ALP up to 3% was acceptable to the panellist. The green colour and soft texture of the noodles did not have a negative effect on the overall acceptability of the noodles. The texture of the 2% ALP-supplemented noodles was the most acceptable, although all other samples were similarly as acceptable. The sample with 3% got the lowest score for taste; however, overall it was more acceptable than other samples. Conclusion and recommendations This study confirmed that instant noodle consumption amongst university students is high. This consumption trend increases the risk of malnutrition as noodles were mostly consumed as a single meal (i.e. without vegetables or other accompanying foods). Amaranthus was an underutilized vegetable amongst the sampled population. Although others may have vast knowledge of the vegetable and its benefits, its consumption is still low. Amaranthus- supplemented noodles show a great potential for acceptability as an innovation. It is recommended that more products with this vegetable are developed so as to re-introduce it to the food system and reduce its stigmatization.
The utilization of amaranthus leaf powder to supplement ujeqe (steamed bread) wheat flour for the alleviation of food and nutrition insecurity in Empangeni South Africa.
(2023) Olusanya, Ruth Nachamada.; Unathi, Kolanisi.; Ngobese, Nomali Ziphorah.; Mayashree, Chinsamy.
Malnutrition persists in many developing countries, leading to an increased concern in the farming sector to deliver at least 70% of food to feed 40% of the anticipated global population of nine billion persons by the year 2050. Such projections call for a keen interest in studies that explore underutilised edible crops for food and nutrition security of the world’s growing population. Malnutrition of all forms including micronutrient deficiencies, “called hidden hunger”, is currently an issue of concern. About 870 million people across the globe are unable to access sufficient nutritious food that optimises dietary needs. Also, 98% of this hungry population live in the developing countries, where 15% of the population is undernourished, Susceptible persons to malnutrition identified include infants, young children, and young women of childbearing age. The impact of malnutrition impairs children’s vision at an early age, slows down cognitive development and retards general development. All forms of malnutrition are nutrient-related preventable challenges; however, it is identified as the leading factor to most morbidity and mortality rates; which limits the livelihoods of many individuals especially smallholder farmers who are residents in informal settlements of urban centres and rural communities. A food-based approach where available nutrient-dense food is incorporated as an ingredient in staple food has been identified as a good strategy to tackle malnutrition. Amaranthus is an ancient C4 plant, a drought tolerant plant that requires little attention yet maximum yield; with huge potential to provide food for nutrition security. Adequate nutrition, at the household level, is indispensable for the proper functioning of the human system and well-being. However, most marginalised, and less privileged people often follow a monotonous starchy/cereal-based diet as this is the available food to fall back on. Extensive studies have shown that about 30 000 varieties of edible plants are dispersed around the world. These plants are cheap, accessible, and highly endowed with medicinal and nutritional benefits. However, only 7000 have been utilised as food while others are underutilised including Amaranthus. It is perceived that most people harvesting Amaranthus leaves for food are the most disadvantaged and marginalised in the rural communities, thus preference issues, perceptions and stigma are linked to Amaranthus underutilisation. Amaranthus seeds have been investigated as enhancers of staple foods. Similarly, leaves of Amaranthus have been identified with great potential to enhance the nutritional value of staple foods for improved nutrition security, optimizing well-being, and improving livelihoods. However, Amaranthus leaves are yet to be explored as a supplement in many traditional foods, including Ujeqe. Online databases of peer-reviewed articles and books were reviewed around the nomenclature, nutritional, and nutraceutical value and objectives were conceived for this study. A mix design (qualitative and quantitative) research method was adopted and a purposive convenience random sampling approach was utilised for the study. Participatory Rural Appraisal (PRA) tools such as transact walks, observation and key informant interviews were conducted. Semi-structured open-ended questionnaires were used to conduct a series of face-to-face interview with six key informants in five markets (n = 30) from urban and rural formal and informal markets where commonly sold/consumed varieties of Amaranthus were identified. Semi-structured questionnaires (100) were administered to gather data around the utilisation of Ujeqe and Amaranthus leaves as potential food for improved nutrition security. A clustered data of (91) respondents was analysed, using descriptive content analysis. The findings of the survey show that Ujeqe is consumed as a meal or as a snack by all people except babies. Also, it is a special meal well appreciated for its simplicity of ingredients and the mode of preparation thus, it is a convenient food that can be served at any time of the day, even in ceremonies, religious functions, and traditional worship of ancestors. Ujeqe’s complementary foods that were identified included legumes and protein-rich foods of animal origin including Usu which are less accessible to the less-privileged hence, some consume it alone as a snack or as a single food. Studies have shown that cereal-based foods without vegetables and fruits are inadequate for optimum well-being because they are lacking/limited in essential nutrients. Amaranthus plants have been investigated as food plant with essential nutrient. Its grains have been used as fortificants, but the leaves have been neglected and its application in Ujeqe steamed bread (USB) is rarely reported in the literature. Amaranthus seeds have been processed into flour and used as food fortificants in staple food. However, the processing of Amaranthus leaves is still very low. Thus, the most common species of Amaranthus grown and sold in formal and informal market in the study site (Amaranthus dubius) was sourced and self-processed into Amaranthus leaf powder (ALP) under a controlled food laboratory environment. The ALP was analysed for macro and micronutrients and utilised to develop 0%, 2%, 4% and 6% prototypes of ALP supplemented Ujeqe which was analysed for macronutrient and micronutrient content. The sensory attributes of ALP supplemented Ujeqe were evaluated using 60 untrained panellists. Moisture content of plain wheat flour (PWF) and ALP in the range 10.6-4.41g; were within the quality shelf-life before usage. The carbohydrate for this study (41.6-74.3g) and fat (1.58- 4.47g) were higher in both raw materials for the study (ALP and PWF). Likewise, the ash (2.37-17.97g) and protein (11.96-31.56g) were recorded as higher in the raw materials for the study. The micronutrient content of the raw materials showed that ALP had a higher nutritional composition than PWF with a statistically significant difference at p < 0.05. Mineral content of calcium was (30.00-2600mg), magnesium (40-120mg), zinc (3.267-7.068mg), copper (1.00- 17.34mg) manganese (1.434-3.00mg) and iron (7.200-24.00mg). The moisture of the ALP enriched Ujeqe prototypes was low, connoting a keeping quality of the shelf-life of the enriched ALP Ujeqe food products. All the macronutrient nutrients of ALP supplemented Ujeqe (Table 3) were enhanced with increased concentration of ALP. The enrichment was noted in the ash content of the 2% (2.2-0.0g), 4% (2.05-0.01g) and 6% prototypes (2.31-0.03g) respectively, with a statistically significant difference at p < 0.05. Likewise, levels of copper, phosphorus, calcium, zinc, manganese, and iron were recorded. All supplemented Ujeqe were enriched in nutrient content. The sensory evaluation indicated that all samples were acceptable. The 6% ALP Ujeqe prototype was the most enriched, but the 2% sample was the most acceptable prototype compared to the control sample followed by 4% and 6% respectively. There was no statistically significant difference in the overall consumer acceptability level of the enriched sample when compared with 0%, 2% and 4% ALP supplemented prototypes. The ALP supplemented Ujeqe was enhanced both in macro and micronutrients. The high ash content of the food samples in this study connotes ALP-supplemented sample richness in mineral content. The mineral content of the raw material, ALP was significantly higher than PWF, supplemented Ujeqe with 6% ALP containing the highest mineral content. Hence, from the nutritional point of view, the formulation was enriched significantly in some selected mineral content. Therefore, ALP supplementation in staple foods like Ujeqe can be a potential foodbased approach that is cost-effective and a sustainable measure for addressing food and nutrition insecurity, especially among the malnourished population. Fibre was not analysed in this study. Thus, future studies can explore ALP-supplemented Ujeqe’s fibre content and microbial tests can be carried out to determine its shelf stability. Continuous research around underutilised food plants including Amaranthus for food and nutrition security can be explored in other staple foods as viable measures to tackle nutrition security. Also, the need for effective implementation of relevant research to help in the domestication of Amaranthus cannot be overemphasised. Thus, improving the small-scale farming of Amaranthus to a larger scale appears to be a realistic way forward. Therefore, the South African government should assist small-scale farmers of Amaranthus with all the extension services needed as this may enhance their productivity and provide food and nutrition security for the community. Similarly, policymakers should consider the provision of land, finance, fertiliser, seeds, herbicides, fences, insecticides, and grants to encourage farmers to plant leafy vegetable foods like Amaranthus for nutrition security. Enhancing small-scale farmer’s capital should involve financial support from the government and the provision of land.