Study On The Antimicrobial Effects Of Spices And The Preservation Technology On Low-salt Sauce

With the development of modern science and technology, consumption level of the public has improvemented greatly. People pay more and more attention to the diet health and safety. The harm of high salt content to people has been recognized gradually. At present, salt content in commercial sauce are higher commonly, so low-salt sauce will become the development trend gradually. The inhibitory effects of salt on spoilage microorganisms will greatly fall by reducing the salt content, and the shelf-life will be shortened. The development of the sauce industry is hindered seriously.The salt content of commercial sauce was measured and the salt content with less than 5% as the low-salt scope was selected in this study. According to the conditions of fermentation of sauce, fermentation temperature, fermentation time, salt addition as the investigated factors were selected. Through the orthogonal design, the amino nitrogen content as the indicators to get the optimal fermentation conditions was taken. The optimization results were as following: fermentation temperature was 40℃, fermentation time was 13d and 5% salt addition. Under these conditions, the amino nitrogen content of low-salt sauce reached 0.978%, and in line with the national health standards.The spices, which had better antimicrobial effects, were chosen through comparing the inhibitory effects of six natural spices on the main microorganisms in low-salt sauce. The inhibitory effects and synergisitic antimicrobial effects of their extracts were studied with the filter paper disc agar diffusion method. The results showed that six natural spices showed different antimicrobial abilities. Clove and cinnamon had the more intensive antimicrobial effects. The antimicrobial effects of their alcohol extract were better than their water extract, and the antimicrobial effects of clove alcohol extract were better than cinnamon alcohol extract. There were synergistic or antagonistic effects, when their alcohol extracts were mixed with different ratios. There had synergistic antimicrobial effects when cloves and cinnamon alcohol extracts mixing ratio was 3:1(V/V), and the inhibition effects on the three kinds of bacteria were the best.Clove and cinnamon, which had better antibacterial effects, were used on the preservation of low-salt sauce. They were respectively added into the low-salt sauce, and the sauce was storaged at the accelerated temperature. The total number of bacteria, yeasts and molds were measured during the storage period, and the inhibition rate were calculated. The effects of preservation were observed. The optimum amount of single preservatives was determined through considing the economic cost and the impact to the flavor of low-salt sauce. The results showed that:the optimum added amount of clove and cinnamon were 0.5% and 0.6%, and 0.5% was chosen as the added amount of compound preservatives. The preservation effects of compound preservatives were studied when they mixed with different ratios.The results showed that:the preservation effect of low-salt sauce was the best when the mixing ratio was clove:cinnamon 3:2(m/m), and the economic cost also was saved.The low-salt sauce, which cantained clove and cinnamon as the compound preservative, was further processed into low-salt bechamel. The optimal added amount of excipients by sensory evaluation was determined. The quality of final product was examined, and the preservation experiment was done.The results show that:sensory effects of low-salt bechamel were the best, when the ratio of low-salt sauce to edible oil was 1:0.7,3% pepper,2% sesame, 10% peanuts. All indexes reached the national health standard, and the product maintain freshment after 3 months at 25℃.