Substitution of nitrite by Chinese red broken rice powder in Thai traditional fermented pork sausage (Nham)

The objectives of this study were to determine the physical, chemical and microbiological properties and sensory evaluation of Thai traditional fermented pork sausage (Nham) which added Chinese red broken rice powder from Monascus purpureus as a substitute for nitrite. In this experiment, 4 levels (0.1, 0.2, 0.3 and 0.4 g/100 g) of Chinese red broken rice powder were used. The sausages, then, were packed in polypropylene bags and were kept for 24 h at 30°C until sour taste occurred and subsequently stored at chilled temperature (5°C) for 30 days. The color values (L*, a* and b*), titratable acidity, pH, aw values, moisture, protein and fat contents were analyzed. Samples were also examined microbiologically for total plate counts (TPC) and the presence of Clostridium perfringens, Salmonella spp. and Staphylococcus aureus. The results revealed that L* and b* values were the lowest and a* values was the highest in 0.4 g/100 g rice powder added treatment. Lactic acid contents of the samples ranged from 0.91 – 2.47% which was higher than that of the control. The pH of the samples ranged from 3.74 – 4.25 which was dropped to the lowest value (3.74) on day 24 and then increased until day 30. Moisture contents and aw values were slightly changed with no significant difference (P 0.05). The results also indicated that the sausages containing rice powder were not different in protein and fat contents compared with the control. TPC of samples were between 8.65 – 10.99 log CFU/g which was increased to the highest numbers (10.99 log CFU/g) on day 24 until day 30 and pathogenic microorganisms were not found during storage. The appearance and color attribute liking scores in 0.1 g/100 g rice powder added treatment were the highest for up to 12 days.