Abstract：
The impact of paprika and dextrose addition on the surface of dry cured loins was analysed attending to differences in microbiota composition and aroma profile. Three different types of loins containing either dextrose (D), paprika (P) or a mixture of dextrose and paprika (DP) were manufactured. The loins were characterized using physic-chemical parameters, free amino acids, volatile compounds and aroma sensorial analysis, as well as applying microbiological counts and metagenomics of the 16S rRNA gene and its rDNA region. The analysis of volatile compounds clearly distinguished all loins, whereas the total content of free amino acids only separated P from D and DP loins. The main sensory differences were linked to paprika addition, which increased the perception of paprika and smoky odors as well as cured, savoury and cheesy notes. Microbial counts analysis could not differentiate between the three loin types; however, metagenomics analysis revealed clear differences in key bacterial and fungal genera among the three loins. Paprika addition favoured dominance of Latilactobacillus in the microbiota of P loins. On the contrary, dextrose addition caused the dominance of Staphylococcus in the microbiota of D loins. In DP loins, both genera were similarly represented in the bacterial community. Regarding fungi, large differences could be observed within the P and D loins, whereas the proportion of Debaryomyces in DP loins increased. The microbiota composition of DP loins controlled the lipid oxidation phenomenon, reducing the generation of derived volatiles producing rancid notes and increase the volatile compounds derived from amino acids such as branched aldehydes, pyrazines and pyrroles, providing particular aroma notes to the loins.
摘要：
分析了辣椒粉和葡萄糖添加对干固化腰部表面的影响，以考虑微生物群组成和香气特征的差异。三种不同类型的腰部含有葡萄糖(D)，制造辣椒粉(P)或葡萄糖和辣椒粉(DP)的混合物。使用物理化学参数对腰部进行了表征，游离氨基酸,挥发性化合物和香气感官分析，以及应用微生物计数和16SrRNA基因及其rDNA区域的宏基因组学。对挥发性化合物的分析清楚地区分了所有腰部，而游离氨基酸的总含量仅将P与D和DP腰部分开。主要的感官差异与辣椒粉的添加有关，增加了辣椒粉和烟熏气味的感觉，美味和俗气的笔记。微生物计数分析无法区分这三种类型；然而，宏基因组学分析显示，这三个腰部的关键细菌和真菌属存在明显差异。辣椒粉的添加有利于枯草杆菌在Ploins微生物群中的优势。相反,葡萄糖的添加导致葡萄球菌在D腰的微生物群中占主导地位。在DP腰部，两个属在细菌群落中的代表相似。关于真菌，在P和D腰部可以观察到很大的差异，而DP腰部中的去巴酵母的比例增加。DP腰部的微生物组成控制了脂质氧化现象，减少产生酸败的挥发性物质的产生，并增加衍生自氨基酸的挥发性化合物，如支链醛，吡嗪类和吡咯类,为腰部提供特别的香气。
