Effect of hurdle factors on the physicochemical and sensory properties of stored soy milk

Abstract

Soy milk was processed using hurdle factors. Four samples of soy milk were prepared using different processing methods. Soy milk was processed from blanched soybean, steaming for 1 h and packaged in a glass bottle (SNP), blanched and steamed soybean with the addition of 0.5% potassium metabisulphate and packaged in a glass bottle (SCP), blanched and steamed soybean containing 0.5% potassium metabisulphate and 1% clove and packaged in glass bottle (SCC₁), and blanched and steamed soybean containing 0.5% potassium metabisulphate and 1.5% clove and packaged in glass bottle (SCC₂). The convectional soy milk packaged in PET bottles served as the control (CTL). All the formulated soy milk samples were stored for 8 days under ambient condition. The samples were analyzed for physicochemical, microbial and sensory qualities. There was a general decrease (p < 0.05) in the pH, viscosity, total solid and an increase in microbial load during the storage period. The pH and total solid during storage ranged from 6.03 to 6.86 and 6.58 to 11.17%, respectively. The microbial load for the samples ranged from 8 x 10¹ to 2.85 x 10⁶ cfu during the storage period. Sensory scores showed that SNP was most preferred. The result of this study showed that hurdle factors were effective in extending the shelf life of soy milk for up to six (6) days; however, the sensory scores for the samples containing clove extracts were low throughout the period of the study.

Keywords: Soy milk, soybean, hurdle, clove, storage