Xiaoying Li,Chunsheng Liu,Junkai Wu,Xiao Xiao,Libin Zhang,Caixia Chen,Annette S. Wilson,Fuhang Song
To recognize the key ester-related volatile compounds, 5 types of peaches including 54 late-ripening peach materials were examined by headspace solid-phase microextraction coupled with gas chromatography–mass spectrometry and E-nose. Here, a large number of esters were identified to be released by ripe peach fruits and were mainly characterized by fruity, green, and fatty notes. The variety and content of esters had greatly changed within or between cultivars, indicating that the fruit volatiles were highly differentiated depending on the specific genotypes and cultivation conditions. The ester types showed that fatty acid-derived C6 alcohols and methyl-/ethyl- short-chain alcohol were the main ester precursors, which were more likely to be utilized and well selected by alcohol acyltransferases, whereas the preference of acyl donors was not observed. The common peach type, which exhibited a unique volatile profile, displayed broader diversity and more abundant characteristics in ester-related volatiles than the other four types. A total of 19 key esters were identified as the main components and the content of most esters showed no significant difference among different peach types. Some key esters had even been enriched in nectarines. Moreover, the multiple discriminant analysis revealed a possible relationship between peach types and the domestication of the peach evolution. This study investigated ester-related volatiles released by different types of peach fruits and can be further used to evaluate the peach qualities, providing an important reference for peach breeding and processing.
Nectarine fruits are rich in nutrients, which are susceptible to fungal infection during postharvest, resulting in quality deterioration and decay. This study aimed to assess the effect of different concentrations of carvacrol and soy protein isolate coatings on the fungal infection and quality characteristics of nectarines during postharvest storage. The results showed that soy protein isolate carvacrol (SPI-C) coating inhibited the growth of Rhizopus stolonifer in vitro. The SPI-C coating significantly reduced the incidence of postharvest soft rot, maintained the postharvest quality of nectarines during storage. SPI-C coating induces the defense response to soft rot by enhancing the accumulation of phenolic, flavonoids and lignin, and up-regulating the expression of defense-related genes in nectarines. The SPI-C coating activated the transcription of antioxidant enzymes (CAT, SOD and POD) and eliminated ROS damage. The disease resistance response promotes the production of defense-related substances by upregulating the gene expression of PpPPO and PpPAL . In summary, SPI-C coating significantly reduces the incidence of postharvest soft rot, maintains the postharvest quality and induces defense response to soft rot by enhancing the expression of genes involved in phenylpropanoid metabolism in nectarines during storage.
Lei Dou,Zimu Zhang,Xiufang Huang,Yaobing Chen,Kai Luo,Jianquan Kan
Considering that the peptide from Idesia polycarpa Maxim.cake meal polypeptide (CIP) is a novel antioxidant agent, this study aimed to develop an efficient and safe food film by incorporating the CIP agent into a gelatin matrix. The films with different concentrations of CIP were characterised and applied in the preservation of nectarines. The results indicated that the CIPF/3% fraction exhibited significant moisture barrier properties, with a water vapor permeability (WVP) of only 8.12 % ± 0.09 %. Additionally, it demonstrated excellent mechanical and antioxidant properties, with scavenging capacities of 76.31 % ± 0.597 %, 65.98 % ± 0.444 %, and 60.98 % ± 0.231% for DPPH, ABTS, and hydroxyl radicals, respectively, surpassing those of other fractions. In nectarine freshness preservation, the Coating/3% fraction showed the best performance. It significantly reduced the weight loss rate of nectarines, improved fruit firmness, maintained the pH value, and minimized nutrient losses, including ascorbic acid and Total soluble sugars (TSS). Furthermore, it effectively preserved the bright surface color of nectarines and extended their shelf life. In summary, the specific environmental protection, safety, and preservation qualities of the CIPF/Coating in food packaging suggest a promising potential for its application.