ABSTRACT
Peach (Prunus persica) is one of the most important economic fruit crops in the current society. In this study, we reported the complete chloroplast genome sequence of peach cultivar 'Rui Guang 18' (Prunus persica var. nectarina cv. 'Rui Guang 18') using whole genome sequencing data. The complete chloroplast genome size was 157,494 bp as a circle, which contained a large single-copy (LSC) region of 85,848 bp, a small single-copy (SSC) region of 18,983 bp, and a pair of inverted repeats (IRs) region of 52,663 bp. The total GC content of the chloroplast genome is 36.8%. The chloroplast genome contains 116 genes, including 76 protein coding genes (PCG), 6 ribosome RNA (rRNA) genes, and 35 transfer RNA (tRNA) genes. The complete chloroplast genome will be a potential genetic resource for peach breeding.
ABSTRACT
Peach cultivars contribute to unique product characteristics and may affect the degree of browning after high-pressure processing (HPP). Nine peach cultivars were subjected to HPP at 0, 100, and 400 MPa for 10 min. Proton nuclear magnetic resonance (1H NMR) relaxometry, light microscopy, color, polyphenol oxidase (PPO) activity, and total phenols were evaluated. The development of enzymatic browning during refrigerated storage occurred because of damage during HPP that triggered loss of cell integrity, allowing substrates to interact with enzymes. Increasing pressure levels resulted in greater damage, as determined by shifts in transverse relaxation time (T2) and by light micrographs. Discoloration was triggered by membrane decompartmentalization but limited by PPO activity, which was found to correlate to cultivar harvest time (early, mid, and late season). Outcomes from the microstructure, 1H NMR ,and PPO activity evaluation were an effective means of determining membrane decompartmentalization and allowed for prediction of browning scenarios.