Urlings H A, Bijker P G, van Logtestijn J G
Department of the Science of Food of Animal Origin, Faculty of Veterinary Medicine, Utrecht University, The Netherlands.
J Anim Sci. 1993 Sep;71(9):2420-6. doi: 10.2527/1993.7192420x.
In this study, the fermentation of raw, inedible poultry byproducts mixed with sugarbeet pulp and dextrose and inoculated with Lactobacillus plantarum and(or) Enteroccocus faecium resulted in a drop of pH in the byproducts to approximately 4.0 to 4.5 within 48 h. To keep the fermented product stable for a period of 21 d, the addition of > or = 3% (wt/wt) of a fermentable carbohydrate was necessary. With a high inoculation level of approximately 10(8) to 10(9) L. plantarum per gram, or with acidification of the initial mixture with .4% lactic acid, the number of Enterobacteriaceae decreased faster than with inoculation at 10(5) L. plantarum per gram, or without initial acidification. After 21 d of fermentation, a high level of enzymatic breakdown of proteins and amino acids was observed: the nonprotein N level increased from 5% to between 15 and 40% of total N and the volatile N level increased from 1% to between 3 and 11% of total N. An increase in histamine, cadaverine, and putrescine was also observed. Despite the technological measures taken, such as the application of a high inoculum of starter culture and initial acidification with .4% lactic acid, this amino acid breakdown could not be reduced to an acceptable level. These results suggest that, because of biochemical deterioration, fermentation alone is not a useful method of preservation of raw poultry byproducts.
在本研究中，将生的、不可食用的家禽副产品与甜菜浆和葡萄糖混合，并接种植物乳杆菌和（或）粪肠球菌进行发酵，结果副产品的pH值在48小时内降至约4.0至4.5。为使发酵产品在21天内保持稳定，添加≥3%（重量/重量）的可发酵碳水化合物是必要的。接种量约为每克10⁸至10⁹个植物乳杆菌，或用0.4%乳酸对初始混合物进行酸化处理时，肠杆菌科细菌数量的减少速度比每克接种10⁵个植物乳杆菌或未进行初始酸化时更快。发酵21天后，观察到蛋白质和氨基酸有高水平的酶解：非蛋白氮水平从总氮的5%增加到15%至40%，挥发性氮水平从总氮的1%增加到3%至11%。还观察到组胺、尸胺和腐胺有所增加。尽管采取了技术措施，如使用高接种量的发酵剂培养物和用0.4%乳酸进行初始酸化，但这种氨基酸分解无法降低到可接受的水平。这些结果表明，由于生化变质，仅靠发酵不是保存生家禽副产品的有用方法。
