Effects of frying treatments on texture (hardness) and colour parameters (L,a,b,ΔE) during deep fat frying of yellow fleshed cassava root slices (TMS 01/1371) were investigated. Slices (dimension of 40 mm × 25 mm × 3 mm) were divided into three portions and subjected to vacuum frying (fresh slices) and atmospheric frying (fresh and predried slices) and equivalent thermal driving forces (ETDF) of 60°C, 70°C, and 80°C were maintained during frying. The quality attributes investigated were best preserved in vacuum fried chips. The overall colour change in chips fried under vacuum conditions at 118°C and 8 min was the least (21.20) compared to fresh and atmospherically predried ones (16.69 and 14.81, resp.). A sharp reduction in the breaking force was obtained for all frying treatments after 8 min and this effect was the least in vacuum fried chips. First-order kinetics modeled the changes in quality attributes for all the temperatures investigated. Rate constants k (min⁻¹) obtained for vacuum frying were almost equal to that of atmospheric frying while activation energies for hardness and colour change were 53.30 and 467.11 KJ/mol, respectively. Quality attributes studied were best preserved during vacuum frying.

In this study, four commercialized indigenous fermented beverages most highly consumed in Russia (kefir and ryazhenka) and South Africa (amasi and mahewu) were analyzed for their potential health-promoting properties and flavor-forming volatile organic compounds (VOC). The analysis of antioxidant capacity demonstrated superiority of dairy-based beverages (kefir, ryazhenka and amasi) over the corn-based mahewu; however, mahewu outperformed dairy-based beverages in terms of its potential antihypertensive effect (i.e., the ability to inhibit angiotensin I converting enzyme). The fatty acid (FA) content of kefir and ryazhenka were more diverse compared to that of amasi, but included a lesser amount of branched chain FA. In terms of calculated FA nutritional indices (e.g., indices of atherogenicity and thrombogenicity), kefir and ryazhenka performed similarly and significantly better than amasi. The agreement between beverages theoretical flavor profiles, which was obtained based on the flavors of individual VOC, and consumers’ flavor perception allow hypothesizing about the contribution of detected VOC to the overall products’ flavor. The obtained data expand current knowledge regarding traditional fermented beverages and their values in terms of national dietary recommendations. Additionally, reported VOC profiles will promote the inclusion of traditional fermented beverages into the rations based on the flavor pairing concept (which is controversial but widely applied).

Sixty household low water activity foods were examined and a simulative study was conducted in a high sugar, low aw almond and macadamia butter to determine the survival of Bacillus cereus and Staphylococcus aureus ATCC 25923. Results obtained from 60 low aw samples collected at household level had some significant differences (P≤0,05) within food categories amongst the various tests. Spices had the highest number of aerobic bacteria, aerobic spore-formers, anaerobic spore-formers, and S. aureus. Mean aerobic colony counts for nuts and spices were 2.30 log CFU/g and 4.40 log CFU/g, respectively. Pathogens such as Escherichia coli and Cronobacter sakazakii were present in nuts, whilst Salmonella spp. was present in chocolates. This implies that certain low aw foods may present a public health risk. In the simulative study, temperature and high sucrose concentrations played a significant role in the survival of B. cereus and S. aureus ATCC 25923. B. cereus was found to be more osmotolerant at both reduced and elevated temperatures (18°C and 25°C) in the 12% sucrose sample in both butters, whilst S. aureus ATCC 25923 seemed to grow better in sucrose-free samples at both temperatures in both butters. This implies that certain low aw foods may present a public health risk. Also, B. cereus, being a spore-forming bacterium, can be osmotolerant at both reduced and elevated temperatures.

Even though the nutritional and economic values of Solanum lycopersicum (tomato) are substantially impacted by microbial spoilage, the available data on its microbial community, particularly during spoilage, are limited and have primarily been characterized using conventional culture-dependent methods. This study employed a targeted high-throughput next-generation sequencing method to longitudinally characterize the microbial diversity of two South African tomato cultivars (jam and round) at varied storage intervals (1, 6, and 12 days). Throughout the storage period, the bacterial communities of the two cultivars were more diverse than the fungal communities. The microbial diversity of both bacteria and fungi was greater and comparable between the cultivars on day 1, but becomes distinct as the storage period increases, with round tomatoes being more diverse than jam tomato, though, on day 12, jam tomato develops greater diversity than round tomato. Overall, the most abundant phyla (though Proteobacteria was most dominant) were Proteobacteria, Firmicutes, and Bacteriodota in the bacterial communities, while Ascomycota and Basidiomycota formed most fungal communities with Ascomycota being dominant. At the genus level, Pantoea and Klebsiella (bacteria), Hanseniaspora, Stemphylium, and Alternaria (fungi) were prevalent. Taken together, this study casts light on a broad microbial diversity profile thus, confirms the cultivars’ diversity and abundance differences.

As a traditional processing method, the Nine-Steam-Nine-Bask method has been widely used in the special processing of Chinese medicinal materials. With the highly integrated design and innovation of infiltrating equipment, steaming equipment, drying equipment, and other equipment, a new type of integrated equipment for the Nine-Steam-Nine-Bask method was finally developed and successfully applied in Polygonatum cyrtonema processing. Moreover, seven new processes were explored. The longer the steaming time was, the more steaming and drying cycles, the lower the product recovery rate and the higher the energy consumption. The higher the steaming pressure was, the lower the product recovery rate, the higher the energy consumption and the shorter the drying time. The longer the drying time was, the lower the product recovery rate and polysaccharide content, and the higher the energy consumption. The best new process was XGY1, which had the highest overall score. The steaming process was the most time-consuming and energy-intensive production process, followed by the drying process. The obtained results can provide knowledgeable guidance for the further optimization of the integrated equipment of the Nine-Steam-Nine-Bask method and the development and application of technology for processing characteristic Chinese medicinal materials.