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Peaches are subject to flesh softening during postharvest storage and transport, which affects the storage life of the fruit and causes huge economic losses. Previous research has demonstrated that postharvest brassinolide treatment can maintain flesh firmness, ascorbic acid and soluble solids contents, and enhance disease resistance in peach fruits. This study assessed the influence of postharvest brassinolide treatment on the expression of key genes involved in cell wall degradation and the phenylpropanoid pathway in peach fruits by real-time fluorescence quantitative polymerase chain reaction (qPCR). The results showed that brassinolide dipping inhibited the gene expression of pectate lyase 1, polygalacturonase 21 and pectin methylesterase 1, and significantly enhanced the gene expression of peroxidase, cinnamoyl-CoA reductase, phenylalanine ammonia lyase and caffeoyl-CoA-O-methyltransferase 5 in peach fruits. It also increased the gene expression levels of chaleone synthase, chaleone isomerase, dihydroflavonol-4-reductase and flavanone 3-hydroxylase at the early stage of storage. These findings imply that brassinolide can suppress the expression of key genes involved in cell wall degradation and enhance the expression of key genes involved in the phenylpropanoid pathway, thereby delaying peach fruit softening and enhancing disease resistance.

The use of plant essential oils as an antibacterial agent for food packaging has become a new trend. In order to obtain biodegradable films for the preservation of aquatic products, coaxial electrospinning films were prepared by electrospinning using the antimicrobial preservative oregano essential oil (OEO) or its main components as core material, pullulan (Pul) as film-forming substrate, and thermoplastic polyurethane (TPU) as shell material and were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy. Also, its thermal stability, physicochemical properties was determined as well as the release performance of the antimicrobial preservative from the coaxial electrospinning films and its efficacy in preserving the quality of refrigerated Lateolabrax japonicus fillets. The results showed that OEO was effectively encapsulated in the electrospinning fibers, improving the micromorphology, water vapor barrier properties and wettability and significantly reducing the tensile strength (TS), and swelling degree (SD) of the film (P < 0.05), but not changing the thermal stability of the film significantly. The fibers inside the film had a coaxial core-shell structure, and the release behavior of the preservative was a complex coupling of disintegration and dissolution, resulting in controlled OEO release for up to 60 h. In addition, the film effectively inhibited the growth of microorganisms, and thus had excellent preservative effect on fresh L. japonicus fillets. It effectively delayed the deterioration of the smell, texture and apparent quality of the fillets, and extended the shelf life from 8 to 12 d. This study can provide a theoretical basis and technical support for the development of biodegradable antibacterial packaging materials based on biological antibacterial agents.

This research was undertaken to determine expression patterns of vacuolar processing enzyme (VPE) genes in four apple (Malus domestica (Suckow) Borkh) cultivars 'Royal Gala (RG)', 'Golden Delicious (GD)', 'Ralls Janet (RJ)' and 'Fuji (FJ)' during ripening. The results showed that GD and RG had higher respiration rate, ethylene production, content of malondialdehyde (MDA), relative electrical conductivity (REC) and VPE activity than RJ and FJ during ripening. A total of 17 MdVPEs were found to be expressed in four cultivars. These MdVPEs exhibited different expression patterns during ripening of four cultivars. Generally, MdVPEβ1, MdVPEγ2, MdVPEγ4 and MdVPEδ7 might be closely associated with ripening of all cultivars. MdVPEα6 might have a role in the early period of ripening of ACS1–2/-2 (1-Aminocyclopropane-1-carboxylate synthase) homozygous cultivars (RG, RJ and FJ). Our data here would be helpful in understanding the associations between MdVPEs and storage properties of different apple cultivars. [ABSTRACT FROM AUTHOR]

The effect of methyl jasmonate treatment with 10, 100 and 1 500 µmol/L on the preservation effect of "Jinguan" apple fruit during storage at room temperature (20±2) °C was studied. The results show that: at the 21th day, the peak of respiration rate and ethylene release rate in the 1 500 µmol/L MeJA treatment group is 1.07 times and 1.05 times of the control group, respectively, whereas the levels in the 10 µmol/L MeJA group were 26% and 24% lower than those in the control group, respectively. On the 35th day, the hardness, titrable acid and total phenol contents of 1 500 µmol/L MeJA treatment group were 5%, 10% and 9% lower than those of the control group, respectively, while those of 10 µmol/L MeJA treatment group were 1.05 times, 1.07 times and 1.04 times of that of 100 µmol/L MeJA treatment group, respectively. On the 35th day, MDA content and O2- ⋅ production rate in 10 µmol/L MeJA treatment group were 14% and 12% lower than those in the control group, respectively. They were both 5% lower than those in 100 µmol/L MeJA treatment group, and 1.06 and 1.16 times higher than those in 1 500 µmol/L MeJA treatment group. 10 µmol/L MeJA treatment had better preservation effect, while 1 500 μmol/L MeJA treatment had the opposite effect, accelerating fruit ripening and senility. The study provides reference for the development of new preservation technology for apples. [ABSTRACT FROM AUTHOR]

To investigate the effect of hypobaric storage on the ripeness progress and antioxidant capacity of 'Nanguo' pear, pears at commercial ripeness stage were used as experimental materials and stored under 2 kPa and 25 kPa low pressure conditions for one month before being transferred to the condition of (20±2) °C and 101 kPa to simulate the ripening progress and observe their ripening quality and antioxidant capacity. The results showed that 2 kPa and 25 kPa hypobaric conditions could maintain the ripening quality of @Nanguo@ pears, the yellowing of the fruit peel, and the reduction of fruit firmness, total phenolic and flavonoid contents were inhibited. The contents of soluble solids and titratable acids were maintained well. The appearance of respiratory peak and decreased ethylene release were delayed. Meanwhile, the activity of polyphenol oxidase was decreased, and peroxidase activity was increased. Notably, 2 kPa hypobaric storage at (4±2) °C performed better to delay the ripening process of @Nanguo@ pears after storage, and their antioxidant capacity was also maintained well. [ABSTRACT FROM AUTHOR]