Background: Consumer interest in convenience foods is a new trend worldwide that is expected to increase due to busy lifestyles. Studies have shown that sweet potato has unique nutrients, which if incorporated into cheese can make it a functional food. Food product development process requires that before a product is commercialized, it is subjected to consumer acceptability and shelf-life tests. Objective: This objective of this study was to determine the sensory acceptability and shelf life of mozzarella cheese that was enriched with orange-fleshed sweet potato to improve fiber content. Method: Mozzarella cheese was prepared with orange-fleshed sweet potato powder at 0% up to 5.5% at intervals of 0.5% and a seven point hedonic scale was used to evaluate product acceptability based on colour, aroma, acidity, texture, and fibrousness. Cluster analysis and principal component analysis were carried out using Minitab® software. For shelf life, total coliform count, E. coli, and yeasts and moulds counts were used. Result: Hedonic scores for all sensory attributes except color were not significantly (p>0.05) different between control and treatments. Cluster analysis grouped the sensory attributes into 3 clusters (1-color; 2-aroma, texture and fibrousness; 3-taste and acidity). All the sensory attributes loaded positively on component 1, while taste, acidity, and fibrousness loaded negatively on component 2 of principal component analysis. Fresh cheese had no coliforms, E. coli, yeasts and molds. The yeasts and molds were used to predict shelf life and their numbers were directly proportional with the cheese storage period. The control samples had the longest predicted shelf life of 42 days and the shelf life decreased with increase in orange-fleshed sweet potato incorporation with a treatment of 5.5% orange-fleshed sweet potato having 29 days. Conclusion: Orange-fleshed sweet potato (OFSP)-enriched mozzarella cheese had similar sensory acceptability as the control without OFST. It should therefore be promoted as a functional food with a possibility of using food grade anti-mold agents for extended shelf life.

Platform tests are usually simple and rapid quality control tests which serve as a basis for accepting, setting aside or rejecting raw milk. Some of the rapid antibiotic residues test kits available in the Kenyan market include: Delvo test Fast BL, Delvo Sulphadiazine Penicillin No Tablet (SPNT), Mtusbio Betalactam BLQ Rapid Test Kit and Ringbio beta-lactam, tetracycline, sulfa drugs, BTS 3 in 1 TriTest S. Ndungu Antibiotic residues (NAR) is a colour comparison test that is simple, rapid and does not require electric power in its analysis procedure. This study compared these four rapid antibiotics tests with novel NAR test method in terms of sensitivity and specificity. A total of 28 samples were prepared; 8 milk samples without residues were spiked with milk known to have beta-lactam residues while 10 had no residues and 10 had known beta-lactam (benzyl penicillin) residues. The four analysis methods were carried out as described in their technical bulletins and manuals. For the NAR test, 50 mg of its active ingredient was mixed with 3 ml of milk and colour change observations made. The sensitivity and specificity of the NAR test was found to be 66.7 and 100% respectively while for all the other four tests, sensitivity and specificity was established to be 100% for each. The Kappa coefficient was 0.5882 which indicates moderate agreement, between NAR test method and the other test methods, according to Landis-Koch scale. The odds ratio exhibited positive association between the NAR test and the four methods. NAR test is best applicable at the milk collection routes or farm level before bulking for transportation.