46H-6 |
Effects of sodium nitrite content on formation of volatile compounds in nham (Thai fermented sausage) |
P. Rotsachakul and S. CHAISERI. Dept. of Food Science & Technology, Kasetsart Univ., Paholyothin Rd., Jatujak, Bangkok, 10900, Thailand Nham is a soft fermented pork sausage that is widely consumed in Thailand. The main differences of nham from western sausages are the use of rice and use of more garlic in its formulation. Not much work had been conducted on the flavor of nham. This study was performed to investigate flavor compounds and the impact of sodium nitrite on the production of volatile compounds in nham. Samples with 0, 50, 125 and 500 ppm sodium nitrite were incubated at 30 °C for 3 days. Volatile compounds were extracted from the samples every day by a dynamic headspace sampling method and identified by gas chromatography/mass spectrometry (GC/MS) analysis. A total of 94 compounds were identified: 7 hydrocarbons, 9 aldehydes, 6 ketones, 17 alcohols, 15 esters, 27 sulfur-containing compounds, 2 acids, 1 terpene, 1 furan, 2 halogenated, and 4 miscellaneous compounds. The most abundant chemical group was sulfur-containing compounds that continuously increased in all samples regardless of sodium nitrite concentrations. During fermentation, alcohols, acids, and esters continuously increased in all samples. Nham with 125 ppm sodium nitrite had the highest ester, alcohol, and ketone concentrations. Addition of 500 ppm sodium nitrite slowed down microbial activities, thus retarding the formation of those compounds and causing accumulation of butanoic acid. The sensory analyses showed that nham with 500 ppm sodium nitrite had the lowest intensity of fermented, acid, and overall nham aroma (p<0.05). There was no difference (p<0.05) in aroma quality between nham with 50 and 125 ppm sodium nitrite despited their differences in volatile compound concentrations. This study identified the volatile compounds in nham. Excessive use of nitrite (500 ppm) reduced the amount of esters, alcohols, and ketones, especially those with 4-5 carbon number.
Session 46H, Religious & Ethnic Foods
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