The impact of low-oxygen (2 kPa) controlled atmosphere storage on the recovery of aroma biosynthesis in ‘Golden Delicious’ (GD) apple tissues during their subsequent shelf life was investigated. The results showed that the highest ester content was found in skin tissue, followed by Flesh 2 and Flesh 1. The 2 kPa O₂ storage of GD apples resulted in a decrease in the emission of volatile esters and alcohols, but an increase in aldehyde emission. Notably, compared with skin tissue, the flesh tissue of 2 kPa O₂-stored GD apples had a relatively high recovery capacity of ester biosynthesis but a low recovery capacity of alcohol synthesis for its shelf life. The impact was associated with increased levels in the MdLOX1a and MdAATs (MdAAT1 and MdAAT2) transcripts, as well as a decreased level in the MdHPL transcript in the flesh tissue. In addition, a complex regulatory network of ethylene on fruit aroma biosynthesis in response to low-oxygen conditions was also indicated. Collectively, there was a tissue-specific recovery capability of aroma biosynthesis in GD apples after low-oxygen storage. Full article

Two rootstock hybrids of sweet melons and watermelons (“Kickstart” and “Carnivor” Cucurbita moschata × Cucurbita maxima) grafted onto two watermelon cultivars (scions), “Honeygoal” and “Honeyval”, were examined in this study to determine whether functional compounds, antioxidant properties, and volatile compounds were retained after five days of cold storage at 5 °C and 85% RH following harvest. An interaction exists between cultivars, rootstocks, and storage for total phenolic content, ascorbic acid, chlorophyll content, antioxidant activities, and volatile compounds. Generally, all functional compounds and antioxidant properties decreased during storage; however, “Honeygoal/Carnivor” in cold storage for 7 days retained the total phenols, ascorbic acid, chlorophyl contents, DPPH (15.47 IC₅₀ mg/mL), ABTS (1.06 IC₅₀ mg/mL) scavenging activities, and antioxidant power (IC₅₀ mg/mL) higher than ungrafted, “Honeyval” or “Honeygoal/Kickstart”, “Honeyval/Carnivor” or “Honeyval/Kickstart” melons. The heat map showed a higher abundance of volatile compounds in “Honeygoal/Carnivor” and “Honeyval/Carnivor” melons stored for 7 and 14 days while “Honeygoal/Kickstart” or “Honeyval/Kickstart” requires 14 days of storage. “Honeygoal/Carnivor” and “Honeyval/Carnivor” melons stored for up to 7 days in cold storage were preferred by panelists. Hence, grafting “Honeygoal” melons onto “Carnivor” rootstocks helped to improve the functional compounds, antioxidant properties, and volatiles during storage for 7 days after harvest. Full article

Calafate (Berberis microphylla G. Forst) is an evergreen shrub with blue berries that grows naturally in Patagonia, in South America. It has beneficial nutraceutical characteristics for human health. The objective of the research was to evaluate the effect of different harvest dates of calafate clones in the south-central zone of Chile on the polyphenolic content, antioxidant capacity, quality parameters and fruit yield. To meet this objective, during three consecutive years, four wild calafate clones located in the town of San Ignacio, Chile, were selected. Where a harvest period was established from 110 to 140 days after full bloom (DAFBs), each of the harvests carried out were used for the following measurements: antioxidant capacity, determination of anthocyanin content, concentration of polyphenols, phenolic compounds, soluble solids, total titratable acidity, pH, fruit yield and quality. Among the main results, it can be highlighted that clone 2 was the one that obtained the highest concentration of soluble solids, with 38.0 °Brix at 140 DAFBs. Together, it was the one that obtained the highest content of total polyphenols and concentration of anthocyanins, with 1121 g GAE kg⁻¹ fw and 714 g cy-3-glu 100 g⁻¹ fw, respectively. Full article

Apples have long been known for their beneficial effects on human health due to the presence of various bioactive compounds. It is therefore very important to understand the biophysical properties of apple cuticle that dictate apples’ storability and quality. The purpose of this work was to determine the roughness, hydrophobicity, surface potential, and color of various autochthonous and new apple cultivars. The surface roughness was measured by optical profilometer, hydrophobicity by tensiometer, zeta potential by electro kinetic analyser, and surface color by chroma meter. Measurements reveal that the new cultivar Elstar has the roughest surface while the autochthonous cultivar Crown Prince Rudolph has the lowest roughness. Under normal physiological conditions, all apple surfaces were negatively charged, with Wax apple having the lowest and Crown Prince Rudolph the highest values; most cultivars had an isoelectric point at around pH = 3. The surfaces of the new cultivars were slightly more hydrophobic than those of the autochthonous. We conclude that autochthonous and new apple cultivars differ in biophysical surface properties, which might impact transpiration, bacterial/fungi adhesion and, consequently, apple storage and shelf life potential. Full article

Radish is a root vegetable of the Brassicaceae family that is grown and eaten all over the world. It is often consumed raw as a crisp salad vegetable with a strong flavor. Therefore, this study aimed to clarify the stimulating effect of different γ-rays dose levels (0.0, 10, 20, 40, and 80 Gy) on the quality properties of radish, in addition to its nutritional elements, as well as some of the metabolites found in the red radish roots. The results indicated that the irradiated seeds showed a high germination rate of ≥96% for dose levels of ≤20 Gray (Gy). In addition, the use of gamma rays had a stimulating effect on the vegetative growth, particularly at the doses of 10 and 40 Gy, which provided the largest values of plant height (32.65 cm) and leaf number/plant (8.08), respectively, whereas all the irradiation treatments led to a rise in the length and width of leaves. However, the maximum root characteristics (length, diameter, size, and weight) were confirmed at the dose of 20 Gy (17.51 cm, 5.45 cm, 85.25 cm³ as well as 78.12 g, respectively). It was also noted that the content of plant pigments was significantly higher at a dose of 20 Gy. Additionally, there was an increase in the content of vitamin C using gamma rays, and the highest content (19.62 mg/100 g FW) was at the dose of 20 Gy. The use of γ-radiation caused an increase in some metabolite contents, such as anthocyanin, phenols, and flavonoids, which resulted in an enhancement in the antioxidant activity, achieving the greatest value at the dose of 40 Gy. Exposure of red radish seeds to gamma irradiation before cultivation improved the root contents of the elements (N, K, S, P, Ca, and Mg). The results indicated an increase in the content of organic acids (oxalic, succinic, and glutaric acids) using the radiation dose of 20 Gy, except for malic acid, which had the highest value at a dose of 80 Gy. Similarly, the amino acid pool was significantly increased by irradiation, and the levels of amino acids, which act as originators of the glucosinolate (GLS) phenylalanine, tyrosine and methionine), increased after exposure to gamma radiation, especially at doses of 40 and 80 Gy. Therefore, the red radish roots produced from seeds exposed to gamma rays were of high quality and nutritional value compared to those obtained from un-irradiated seeds. For this reason, gamma-rays are one of the tools that are utilized to improve the growth and quality of crops, especially in low doses. Full article

Postharvest period is a process of natural maturation and senescence. The peel structure and antioxidant capacity of pears are the most important factors that affect its postharvest quality. However, the changes in pear peel properties are still unclear during shelf life. In this study, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were used to investigate the ultrastructural characteristics of pear peel during shelf life, and to determine the changes in peel antioxidants, active oxygen scavenging enzymes, and antioxidant capacity. The results showed that after a 30-day shelf life, the peel cuticles of all tested varieties had varying degrees of color loss and withering, and the integrity of the cells of peel was also damaged, but the surface layer cells of Xuehuali (XH), Huangguan (HG), and Yali (YL) were smoother than Wonhwang (WH) and Housui (HS), and the integrity of the peel cells was also better. In this experiment, there were significant differences in the contents of total polyphenol and total flavonoids among different varieties, and also significant differences in the variation range and variation trends in the activities of peroxidase and catalase (p < 0.05). The total antioxidant capacity of YL pear peel was the highest (68.76 Ug⁻¹), while that of WH pear peel was the lowest (26.37 Ug⁻¹). In conclusion, YL and XH, the representative varieties of White Pear, have better skin structure stability and antioxidant capacity than Sand Pear varieties HS and WH. The overall results provide a theoretical basis for further structure and function investigation of pear peel. Full article

Halyomorpha halys is an important invasive pest that causes severe damage to fruits and vegetables. Peppers are susceptible to infestation by H. halys, resulting in yield losses. Plants respond to the insect infestation with a metabolic response. With this study, we attempted to determine the intensity of the metabolic response of infested peppers, how pungent and non-pungent peppers react to the infestation, and how the H. halys affects the post-harvest quality of both cultivars. The shelf life of the infested peppers did not change compared to the control treatments. We observed a drastic decrease in metabolite levels after storage in all three treatments in both cultivars, especially capsaicinoids, with an approximate decrease of 30% in the pericarp and 95% in the placenta of the pungent ‘Eris F1’. In some cases, the accumulation of metabolites was not limited to the fruit exposed to the H. halys infestation, but to the entire plant. We observed a 15-fold increase in capsaicinoid content in the infested fruits of cultivar ‘Eris F1’ and a 4-fold increase in the pericarp of cultivar ‘Lombardo tago’, which could lead to a possible further study on the defensive function of capsaicinoids and their use against H. halys. Full article