Susceptibility of selected commercial yeasts to autolysis for yeast extract production

A journal article on susceptibility of selected commercial yeasts to autolysis.Ten yeasts comprising nine Saccharomyces cerevisiae and one S.carlsbergensis were assessed for their susceptibility to autolysis for yeast extract production. The work was done in the period April to June, 2000. Each strain was autolysed in distilled water (pH 6.5) at 45°C for 6 hours and dry weight losses, release of proteins into the medium and pH monitored. Dry weight losses appeared to be the most discriminatory evidence of autolysis. Saccharomyces cerevisiae Y1045 and Y58 showed 25.0 percent and 23.9 percent dry weight losses respectively; the other strains autolysed less rapidly. Lactobacillus bulgaricusgrew comparably well in a basal medium supplemented with 5 percent (v/v) of S. cerevisiae Y1045 autolyzate, and in the same basal medium supplemented with 0.5 percent (w/v) commercial yeast extract. The study showed that S. cerevisiae Y1045 has the potential for use in yeast extract production

Acceptance of a complementary food prepared with yellow, provitamin A-biofortified maize by black caregivers in rural KwaZulu-Natal

Objectives: The objective was to assess the sensory acceptability and consumer perceptions of soft porridge made with yellow, provitamin A-biofortified maize by black African female infant caregivers from rural KwaZulu-Natal.Design: This was a cross-sectional study.Setting: The study was conducted at Edendale Hospital, located in the uMgungundlovu District, KwaZulu-Natal province. The hospital serves a high proportion of people from rural areas in this district.Subjects: Sixty black African female infant caregivers participated in the study.Outcome measures: The sensory acceptability of soft porridge made from two varieties of provitamin-A biofortified maize and one variety of white maize were evaluated by black African female infant caregivers (n = 60) using a five-point facial hedonic scale. Some of the subjects (n = 21) participated in focus group discussions to assess consumer perceptions.Results: There was no significant difference in the sensory acceptability of the biofortified maize porridge and the white maize porridge, irrespective of caregiver age (p-value > 0.05). The caregivers expressed a willingness to give their infants porridge made with provitamin A-biofortified maize if it was more affordable, readily available and beneficial to health.Conclusion: The biofortified maize soft porridge was found to be as  acceptable as the white maize soft porridge to black African female infant caregivers from rural KwaZulu-Natal. Provitamin A-biofortified maize has the potential to be used as a complementary food item that would contribute to the alleviation of vitamin A deficiency

Customer Acceptance of Self-Service Technology at Fast Service Restaurants in Tshwane

Objective: Technological advances have prompted many businesses to introduce self-service technology (SST) to improve customer waiting times and reduce operational costs. This study aims to determine the factors linked to the acceptance of self-service technology by customers at fast-service restaurants. Research Design & Methods: This research uses a quantitative method by surveying 172 customers who had visited self-service restaurants within the preceding six months. The Unified Theory of acceptance and use of technology (UTAUT) was used to determine the factors linked to the acceptance of self-service technology at quick-service restaurants. The Statistical Package for Social Sciences was used for analysis. Findings: It was found that age and gender moderate the relationship between the construct: performance expectancy ratio and SST usage intention, effort expectancy and SST usage intention, social influence and usage intention and lastly, age moderates the relationship between facilitating conditions and SST usage behaviour. Contribution & Value Added: The design of future self-service technology at restaurants should be constructed in a manner that would appeal to customers of all ages and gender. An education drive should be prioritised to educate customers about the benefits of self-service while ensuring that they also understand that technology does not reduce employment but may be used to create employment in other forms. Future studies should also investigate whether technology education might have a moderating effect on technology

Nutritional quality of a ready-to-use food, and its acceptability to healthy and HIV-infected children receiving antiretroviral treatment

Objectives: The objectives of this study were to determine the nutritional quality of a ready-to-use food (RUF), and its acceptability to children who were “healthy” and to those who were human-immunodeficiency virus (HIV)-infected and receiving antiretroviral therapy (ART).Design: This was a cross-sectional survey that assessed the consumer acceptability of the RUF by the children.Setting and subjects: One hundred and eighty-eight children were selected from six schools, a day care and a hospital in Pietermaritzburg. Of these children, 123 were “healthy”, and 65 HIV-infected and receiving ART.Outcome measures: The outcome measure of the study was the nutritional quality of the RUF in terms of its nutrient levels relative to appropriate nutritional standards, and its acceptability rating by the children.Results: The RUF had appreciable levels of energy (2 624 kJ/100 g) and protein (15.7 g/100 g).The nutritional composition met the World Health Organization/World Food Programme/the United Nations Standing Committee on Nutrition/The United Nations Children’s Fund recommendations for an RUF regarding energy, protein and essential amino acid levels. Sensory evaluation indicated that the RUF was acceptable to both children who were healthy and to those who were  HIV-infected. Generally, more than 75% of the participants in both groups rated the product overall as “good”. More than 65% of the children liked the taste, smell and mouth feel.Conclusion: The RUF that was used in this study is a good source of energy and quality protein, and is acceptable to children. Further micronutrient analysis would determine the additional role of the RUF in alleviating micronutrient deficiencies, including vitamin A, zinc and iron. Since the RUF is acceptable to children who were healthy and to those who were  HIV-infected on ART, it can be used to address proteinenergy malnutrition in these target groups

Performance of broiler chickens fed South African sorghum-based diets with xylanase

Two experiments were conducted to determine the influence of sorghum variety and xylanase on performance of broiler chickens. In Experiment 1A, a total of 240 day-old Ross broiler chickens were assigned to a 2 (sex) × 3 (sorghum variety) × 2 (with or without xylanase) factorial arrangement in a completely randomized design with 20 chickens per treatment. Gross performance measurements were assessed at 7, 14, and 21 days of age. Carcass yield and visceral organ weights were measured at day 21. In Experiment 1B, a total of 108 female Ross 308 broiler chickens were randomly assigned to a 3 (sorghum variety) × 2 (with or without xylanase) factorial arrangement in a completely randomized design with 6 treatments replicated 6 times. On day 25, all birds were euthanazed by intravenous injection of sodium pentobarbitone and digesta contents from the distal ileum were collected to determine the nutrient digestibility. Broiler chickens offered sorghum variety Pan8816 supplemented with xylanase had higher feed intake, weight gain, and similar feed conversion ratio at 1 - 7 days of age. Breast meat of broiler chickens was not affected by variety or xylanase. The small intestine was heavier in the Pan8625 and Pan8816 groups with xylanase than in the similar Pan8906 group. Enzyme inclusion increased the crude protein digestibility. When xylanase was included in all sorghum varieties, numerically, starch digestibility tended to improve. Sorghum variety affected the growth performance of broiler chickens. Furthermore, nutrient digestibility was affected by the differences in variety.Keywords: Digestibility, tannin, poultry, visceral organs, xylanas

Consumer acceptance of yellow, provitamin A-biofortified maize in KwaZulu-Natal

Objectives: To assess the acceptance of popular maize food products (phutu, thin porridge and samp), prepared with yellow, provitamin A-biofortified maize varieties, in 212 subjects between the ages of three and 55 years, from rural KwaZulu-Natal.Design: A cross-sectional study.Method: Preschool, primary school and secondary school subjects were randomly selected from two primary schools and one secondary school, respectively, while adult subjects constituted a convenience sample. Pre- and primary school children completed a paired preference test. Secondary school and adult subjects completed a five-point facial hedonic and a preference ranking test. Focus group discussions were conducted using adult subjects.Results: Preschool children preferred yellow maize to white maize food products: phutu (81% vs. 19%; p-value < 0.001), thin porridge (75% vs. 25%; p-value < 0.001) and samp (73% vs. 27%; p-value < 0.001). There was no statistically significant difference in preference for white and yellow maize by primary school children. Secondary school and adult subjects preferred white maize to yellow maize. Focus group discussions confirmed the preference for white maize by the adults.Conclusion: The study findings suggest that yellow, provitamin A-biofortified maize has the potential to succeed as a new strategy of dealing with the serious problem of vitamin A deficiency, especially among children of preschool age. However, in older groups, this strategy is unlikely to be successful, unless other strategies are implemented, including intensive nutrition education programmes on the nutritional benefits of the maize, targeting the market price at which yellow maize is sold, increasing its availability in local grocery stores, and improving its sensory properties through breeding.Keywords: yellow maize, provitamin A, vitamin A deficiency, consumer acceptanc

Acceptance of a ready-to-use supplementary food by stable HIV-treated and HIV and tuberculosis (co-infected)-treated patients

Objectives: The objective of the study was to determine consumer  acceptance and perceptions of a ready-to-use supplementary food (RUSF)by subjects treated for human immunodeficiency virus (HIV) and HIV and tuberculosis (co-infected subjects).Design: A cross-sectional study was conducted.Subjects: One hundred and thirty-nine stable HIV-treated and HIV and tuberculosis (co-infected)-treated patients participated in the study. Sixty-eight healthy subjects served as the control group.Setting: The setting was Northdale Hospital and Grey’s Hospital in  Pietermaritzburg, KwaZulu-Natal.Outcome measures: Acceptance of the RUSF was assessed using a five-point facial hedonic scale by stable HIV-treated and HIV and tuberculosis (co-infected)-treated patients (n = 139) from Northdale Hospital and Grey’s Hospital in Pietermaritzburg, KwaZulu-Natal. Perceptions of the RUSF were determined through focus group discussions in which HIV-treated and HIV and tuberculosis (co-infected)-treated patients (n = 43) participated.Results: The overall acceptance of the RUSF was significantly associated with the health status of the subjects (p-value < 0.05). Overall, the product was liked by more than 90% of the HIV-treated and HIV and tuberculosis (co-infected)-treated individuals compared to 85% of the control group. More than 90% of the HIV-treated and HIV and tuberculosis   (co-infected)-treated individuals liked the taste, compared to 87% of the control group. The colour and mouth feel were rated to be “good” by more than 80% of the HIV-treated and HIV and tuberculosis (coinfected)-treated group, compared to approximately 70% of the healthy group. Focus group discussions revealed that the subjects perceived the mouth feel of the RUSF to be “rough”, and that as a health supplement, the RUSF should be provided free of charge, or at a reasonable cost, at public health centres.Conclusion: The RUSF was found to be highly acceptable to stable   HIV-treated and HIV and tuberculosis (co-infected)-treated subjects, although concern was raised about the mouth feel

Hardness changes and endosperm modification during sorghum malting in grains of varying hardness and malt quality

This study examined the interaction between sorghum grain hardness and sorghum malt quality in terms of diastatic power and free amino nitrogen with endosperm modification during malting. The changes in kernel hardness during malting of four commercial sorghum cultivars of differing quality in terms of endosperm texture and potential malt quality were measured using tests for hardness and density, and endosperm modification was followed by scanning electron microscopy. The general pattern of modification during sorghum malting was confirmed to start at the ensdosperm-scutellum interface, then into the floury endosperm towards the kernel distal end. Significantly, a cultivar of intermediate hardness and low malting quality remained harder and modified more slowly than a harder cultivar of high malting quality. It appears that intrinsic grain hardness and malt amylase and protease activity both affect malt hardness and endosperm modification, but amylase and protease activity have a greater effect due to their degradation of endosperm starch and protein. Of the hardness and density tests studied, the Tangential Abrasive Dehulling Device (TADD) gave the best measure of hardness throughout malting; maximum range 24% to 100% kernel removed over 5 days malting. Also, the data agreed with the observed malt modification rates. Thus, the TADD may have application as a simple and rapid test for estimating sorghum malt quality.International Sorghum and Millet and other Grains Collaborative Research Support Program (INTSORMIL)http://www.nonprofitjournals.org/journals/cereal_chemistry.htmhb201

Root-hair endophyte stacking in finger millet creates a physicochemical barrier to trap the fungal pathogen Fusarium graminearum

The ancient African crop, finger millet, has broad resistance to pathogens including the toxigenic fungus Fusarium graminearum. Here, we report the discovery of a novel plant defence mechanism resulting from an unusual symbiosis between finger millet and a root-inhabiting bacterial endophyte, M6 (Enterobacter sp.). Seed-coated M6 swarms towards root-invading Fusarium and is associated with the growth of root hairs, which then bend parallel to the root axis, subsequently forming biofilm-mediated microcolonies, resulting in a remarkable, multilayer root-hair endophyte stack (RHESt). The RHESt results in a physical barrier that prevents entry and/or traps F. graminearum, which is then killed. M6 thus creates its own specialized killing microhabitat. Tn5-mutagenesis shows that M6 killing requires c-di-GMP-dependent signalling, diverse fungicides and resistance to a Fusarium-derived antibiotic. Further molecular evidence suggests long-term host-endophyte-pathogen co-evolution. The end result of this remarkable symbiosis is reduced deoxynivalenol mycotoxin, potentially benefiting millions of subsistence farmers and livestock. Further results suggest that the anti-Fusarium activity of M6 may be transferable to maize and wheat. RHESt demonstrates the value of exploring ancient, orphan crop microbiomes