Physical quality, total lactic acid bacteria and Escherichia coli in pork fermented with roasted black glutinous rice (Oryza sativa var. glutinosa)

Wadi is a traditional Indonesian fermented product generally made using rice as a carbohydrate source. The use of roasted black glutinous rice has the potential to improve fermentation quality because it contains starch, anthocyanins, and phenolic compounds that can support the activity of fermentative microorganisms. This study aims to analyze the effect of adding roasted black glutinous rice on the physical characteristics and microbiological safety of pig wadi fermented in bamboo. The study used a Completely Randomized Design with four treatments, namely P0 (white rice), P1 (10% roasted black glutinous rice), P2 (20% roasted black glutinous rice), and P3 (30% roasted black glutinous rice), each repeated four times. Observed variables included pH, water holding capacity, raw loss, cooking loss, total lactic acid bacteria, and the presence of Escherichia coli. Data were analyzed using analysis of variance (ANOVA) followed by Duncan's test at a significance level of 5%. The results showed that the addition of roasted black glutinous rice had a significant effect (P<0.05) on the pH value, but did not significantly affect (P>0.05) on the water holding capacity, raw loss, and cooking loss. The pH value ranged from 5.77–6.35, water holding capacity 66.52–70.11%, raw loss 3.62–6.93%, and cooking loss 25.26–29.79%. Total lactic acid bacteria increased with increasing concentration of roasted black glutinous rice with the highest number in treatment P3 of 2.02 × 10⁸ CFU/g, while E. coli was not detected in all treatments. Increasing the concentration of roasted black glutinous rice was able to support the growth of lactic acid bacteria without reducing the physical quality of the product, thus producing pig wadi with good microbiological safety.