Green Olive Browning Differ Between Cultivars

Comprehensive Review of Olea europaea: A Holistic Exploration into Its Botanical Marvels, Phytochemical Riches, Therapeutic Potentials, and Safety Profile

Human health is now inextricably linked to lifestyle choices, which can either protect or predispose people to serious illnesses. The Mediterranean diet, characterized by the consumption of various medicinal plants and their byproducts, plays a significant role in protecting against ailments such as oxidative stress, cancer, and diabetes. To uncover the secrets of this natural treasure, this review seeks to consolidate diverse data concerning the pharmacology, toxicology, phytochemistry, and botany of Olea europaea L. (O. europaea). Its aim is to explore the potential therapeutic applications and propose avenues for future research. Through web literature searches (using Google Scholar, PubMed, Web of Science, and Scopus), all information currently available on O. europaea was acquired. Worldwide, ethnomedical usage of O. europaea has been reported, indicating its effectiveness in treating a range of illnesses. Phytochemical studies have identified a range of compounds, including flavanones, iridoids, secoiridoids, flavonoids, triterpenes, biophenols, benzoic acid derivatives, among others. These components exhibit diverse pharmacological activities both in vitro and in vivo, such as antidiabetic, antibacterial, antifungal, antioxidant, anticancer, and wound-healing properties. O. europaea serves as a valuable source of conventional medicine for treating various conditions. The findings from pharmacological and phytochemical investigations presented in this review enhance our understanding of its therapeutic potential and support its potential future use in modern medicine.

Genome-Wide Analysis of the Polyphenol Oxidase Gene Family in Olea europaea Provides Insights into the Mechanism of Enzymatic Browning in Olive Fruit

Browning of olive (Olea europaea L.) fruit reduces the sensory and nutritional qualities of olive oil, thereby increasing production costs. Polyphenol oxidases (PPOs) are the key enzymes that catalyze phenolic substance oxidation and mediate enzymatic browning in olive fruit, but the exact regulatory mechanism remains unclear. The main challenge is the lack of comprehensive information on OePPOs at the genome-wide level. In this study, 18 OePPO genes were identified. Subsequently, we performed a bioinformatic analysis on them. We also analyzed the expression patterns and determined the relationship among browning degree, PPO activity, and expression of OePPOs in the fruits of three olive varieties. Based on our analysis, we identified the four most conserved motifs. OePPOs were classified into two groups, with OePPOs from Group 1 showing only diphenolase activity and OePPOs from Group 2 exhibiting both mono-/diphenolase activities. Seven pairs of gene duplication events were identified, and purifying selection was found to have played a critical role in the evolution of the OePPO gene family. A positive correlation was observed between the browning degree of olive fruit and PPO activity across different olive varieties. Moreover, two important genes were found: OePPO-5 the main effector gene responsible for fruit browning, and OePPO-8, a key gene associated with specialized metabolite synthesis in the olive fruit. In short, our discoveries provide a basis for additional functional studies on OePPO genes and can help elucidate the mechanism of enzymatic browning in olive fruit in the future.

Mechanical harvesting at dawn in a super-high-density table olive orchard: effect on the quality of fruits

BACKGROUND

Mechanical harvesting with over-the-row harvesters in super-high-density (SHD) table olive orchards increases the effectiveness of fruit removal, although bruising can limit the fruit quality. Additionally, an early harvest in periods less favourable to quality production is increasingly frequent as a result of global warming. The present study explores the impact on olive quality of harvesting at dawn when the environmental temperature is low. The study was carried out for 2 years on two cultivars with different tolerance to bruising ('Manzanilla de Sevilla' and 'Manzanilla Cacereña'), grown in SHD conditions and harvested at two timepoints: dawn and morning.

RESULTS

Fruit morphology was not modified by the moment of harvest in either of the cultivars. Fruit harvested at dawn produced less CO₂ and ethylene and was less damaged externally and internally compared to fruit harvested in the morning. However, environmental conditions throughout development influenced the response because the highest values of bruising (incidence, area and volume of damaged area), total internal damage and the number of tissue ruptures increased in the year with the hottest summer, and the differences between harvest treatments were less evident.

CONCLUSION

Mechanical harvesting at dawn contributes to reducing the damage in olive fruit. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.