S olanum aethiopicum Extract Used as Coagulant Affected Nutritional and Rheological Characteristics of Cheese

Abstract

White cheeses made using extract from Solanum aethiopicum shum or calf rennet were compared for their microbiological, physicochemical, rheological, and sensory characteristics. Except Staphylococcus aureus which was higher in cheese manufactured with Solanum extract, the microbiological parameter values (coliforms, Lactobacillus spp, Listeria monocytogenes, yeasts/moulds, Escherichia coli, sulfito-reducer germs, Salmonella spp) were similar in all cheeses. In the same way, chemical parameter values (pH, ash, proteins, fats and sugar) were equivalent. Soluble nitrogen values were observed to be higher in the cheese made using Solanum extract than in the cheese made using calf rennet. The values for the non-protein nitrogen did not exhibit any difference according to the type of coagulant used. Textural profile showed different behaviour. However, cheese made with 1x Solanum (low quantity of extract) was close to calf rennet-based cheese. Such a trend was observed for the following parameters: cohesiveness, springiness, chewiness and adhesive strength. Cheese made with calf rennet was statistically harder than that made with Solanum extract. This hardness decreased with Solanum extract quantity. The values for sensory parameters did not show any difference between the 1x Solanum extract and calf rennet, excluding texture (hard, friability and soft). Therefore, the results suggest that Solanum extract might be used successfully to make cheese of acceptable nutritional quality.