褐变常见于苹果加工中,不同的苹果品种。目前的工作调查了Yataka的四个品种苹果的代谢组学,Gala,珊莎,还有富士,具有不同的褐变特性和相关酶。Sansa作为褐变不敏感的苹果品种,4个苹果品种的色度变化最小,PPO活性最低,SOD活性最高。褐变抑制预处理提高了SOD和PAL的活性,降低了PPO和POD的活性。此外,四个苹果品种(FC)之间的代谢组学差异,比较了它们的褐变浆(BR)和褐变抑制浆(CM)。并对关键代谢物进行了深入分析,以匹配相关的KEGG途径和推测的代谢网络。在FC中检测到487、644和494个显著差异代谢物,BR和CM,由脂质组成,苯类化合物,苯丙素类化合物,有机杂环化合物,有机酸,核苷,占23%,11%,15%,16%,11%的总代谢产物。差异代谢物与FC中的39、49和36个KEGG途径相匹配,BR,和CM,分别,其中其他次生代谢产物的生物合成代谢在FC中最为显著,脂类代谢在BR和CM中最为显著,在CM中,能量代谢明显。值得注意的是,Sansa在其BR(484)和CM(342)中显示出最高数量的差异代谢物。Sansa的BR的特征在于黄酮类化合物的生物合成,而其他三个苹果品种与α-亚麻酸代谢有关。此外,在褐变敏感的苹果品种中,褐变抑制预处理显著激活了类黄酮和苯丙素生物合成途径。酚类化合物,脂质,糖,糖有机酸,核苷酸,和腺苷在四个苹果品种中的调控不同,可能作为关键的监管网站。总的来说,这项工作为不同苹果品种的褐变预防提供了新的见解。
Browning commonly appeared in apple processing, which varied in different apple varieties. Present work investigated the metabolomics of four varieties apple of Yataka, Gala, Sansa, and Fuji, which possessed different browning characteristics and related enzymes. Sansa as browning insensitive apple variety, exhibited the least chroma change with the lowest PPO activity and the highest SOD activity among the four apple varieties. Browning inhibition pretreatment increased the activity of SOD and PAL and decreased PPO and POD activity. In addition, metabolomic variances among the four apple varieties (FC), their browning pulp (BR) and browning inhibition pulp (CM) were compared. And the key metabolites were in-depth analyzed to match the relevant KEGG pathways and speculated metabolic networks. There were 487, 644, and 494 significant differential metabolites detected in FC, BR and CM, which were consisted of lipids, benzenoids, phenylpropanoids, organheterocyclic compounds, organic acids, nucleosides, accounting for 23 %, 11 %, 15 %, 16 %, 11 % of the total metabolites. The differential metabolites were matched with 39, 49, and 36 KEGG pathways in FC, BR, and CM, respectively, in which other secondary metabolites biosynthesis metabolism was the most significant in FC, lipid metabolism was the most significant in BR and CM, and energy metabolism was markedly annotated in CM. Notably, Sansa displayed the highest number of differential metabolites in both its BR (484) and CM (342). The BR of Sansa was characterized by flavonoid biosynthesis, while the other three apple varieties were associated with α-linolenic acid metabolism. Furthermore, in browning sensitive apple varieties, the flavonoid and phenylpropanoid biosynthesis pathway was significantly activated by browning inhibition pretreatment. Phenolic compounds, lipids, sugars, organic acids, nucleotides, and adenosine were regulated differently in the four apple varieties, potentially serving as key regulatory sites. Overall, this work provides novel insight for browning prevention in different apple varieties.