Effects of Ultrasound Pretreatment and Dehydration Temperature on the Quality of Dehydrated Soy Cheese (Beske)

ABSTRACT

Soy cheese, locally known as beske is a protein‐rich product from soymilk but is highly perishable with limited shelf life. This study evaluated the effects of ultrasound pre‐treatment on the quality of dehydrated soy cheese to improve its quality. Soymilk was processed into soy cheese, pre‐treated using ultrasound technology, and dehydrated at 50°C, 60°C, 70°C, and 80°C. The samples were analyzed for functional properties, phytochemical and physicochemical properties, microbial count, as well as sensory attributes. Results revealed that beske samples pretreated with ultrasound technology and dehydrated at 60°C had the lowest moisture content (51.07%), retained the highest level of crude protein (18.99%), water holding capacity (1.73 g/g), and swelling capacity (2.03%) compared to the unpretreated, undehydrated, and the unpretreated but dehydrated samples. This beske sample further showed a low pH (6.14) indicating acidity, low phytochemical (oxalate 8.93 mg/100g; phytate 12.34 mg/100g), and low microbial count after 8 days, with bacterial count having 34 × 10 ² cfu/g and fungal count having 16 × 10 ² cfu/g cfu/g. The result of the sensory studies showed that all the samples evaluated scored above average (6.55–7.02), with samples pretreated with ultrasound technology and dehydrated at 50°C and 60°C scoring 6.92 each, whereas the control sample had a significantly higher value of 7.06. It was then concluded that ultrasound pretreatment in combination with controlled dehydration at temperatures between 50°C and 60°C is appropriate for the production of healthy, acceptable, and shelf‐stable soybean products such as beske .