Microbial evaluation of hydrocolloids from flesh and peel of tuber crops flour and sensory attributes of ice cream produced from it

This study assessed the microbial evaluation of hydrocolloids from fresh and peel of tuber crops flour and sensory attributes of ice cream produced from it. White flesh sweet potato and cocoyam were purchased from Ubani market Umuahia, trifoliate yam was purchased from Orie-Ntigha in Isi-alaNgwa North of Abia State and aerial yam from the Abakiliki main market in Ebonyi State. Ice cream ingredients were purchased from Ubani Market in Umuahia of Abia State. Each of the tuber samples (Sweet potato, yams and cocoyam) were washed, peeled and chopped into smaller units of about 5-6 cm long. The peels and flesh were divided into three (3) portions each and were dried to constant weight using sun, air and oven drying methods respectively to obtain chips, followed by grinding into flour samples separately. The flour samples obtained were defatted. The extracts produced were purified and kept in plastic bag and stored in air-tight plastic container prior to analysis. Bacterial and fungal loads in the samples were determined using standard methods. The sensory evaluation of homemade vanilla ice cream was determined based on the method of Iwe (2010). Results obtained showed that the total bacterial count for sun dried and air dried samples ranged from 3.12x 10³ to 3.69 x 10³ CFU/g, while fungi count ranged from 4.21 x 10³ to 4.68 x 10³ CFU/g. Four species of bacteria (Micrococcus, E. coli, Salmonella and Staphylococcus aureus) were identified in the sun-dried and air-dried samples, while 2 species of fungi (yeast and mould) were also detected in the sun-dried and air-dried samples. The oven-dried samples had no microbial growth. Sensory evaluation results showed that ice cream sample produced with oven dried white flesh sweet potato peel hydrocolloids was most preferred.