Understanding the Physiology of Mango?Ripening

The mango (Mangifera indica L.) is one of the most important tropical fruits in the world in terms of production, consumption and nutritional value. Mango production and international trade are expanding and currently, Asia is the main producer, contributing about 74.30% of the world?s mango production. Mango is a climacteric fruit that is harvested at the green ripe stage and then ripened to achieve the desired flavor and texture. Due to the perishable nature of the mango fruit, significant quantitative and qualitative post-harvest losses occur during marketing. It is therefore critical to understand the physiological changes that occur in mango fruit during the ripening process, as this can have a significant impact on the quality, nutritional content and market value of the fruit. A study published in 2019, by the Institute of Agricultural Engineering and Bioeconomy (Germany) and Tshwane University of Technology (South Africa), provides an overview of fruit physiological changes, postharvest quality, and non-destructive evaluation criteria during the mango supply chain. This article summarizes the content on physiological changes in this fruit. Fruit physiology changes throughout the ripening?process The maturity of the fruit at harvest is the key factor in determining the quality and post-harvest shelf life. Mangos are judged on their visual appearance, setting time, size, skin color, shape and absence of defects and rot. Meanwhile, secondary criteria include titratable acid content and color of the flesh, chlorophyll b, total soluble solids and dry matter content. However, consumer interest in internal and nutritional quality is increasing over time. That?s why it is recommended to harvest at the green stage (commercial ripeness), that is, in the middle, physiologically developed, but before the climacteric rise; especially in commercial practices involving storage and transport. Tree-ripened mango fruit has a limited shelf life, resulting in significant loss and susceptibility to disease. To avoid this, mango is harvested at an early stage of maturity, which may affect the physicochemical content and polyphenolic biosynthesis of the fruit and cause chilling injury during cold storage. As mentioned above, mango fruit is a climacteric fruit that enters the ?climacteric? phase after harvesting, so it continues to ripen.? Ripening is the process that involves major changes in physiological, biochemical and organoleptic properties, including increased respiration, ethylene production, biosynthesis of pigments (carotenoids and anthocyanins), metabolic activities leading to changes in carbohydrates, organic acids, lipids, phenolics, volatile compounds, structural polysaccharides and softening of texture to acceptable quality. During fruit ripening, ethylene induces changes that include: (1) flesh color from greenish yellow to yellow to orange in all cultivars; (2) skin color from green to yellow in some cultivars; (3) chlorophyll breakdown and accumulation of carotenoid content; (4) decrease in flesh firmness and increase in juiciness; (5) conversion of starch to sugars; (6) increase in total soluble solids content; (7) decrease in titratable acidity; (8) accumulation of aroma volatiles; (9) increase in CO2 and ethylene production rate. Mature green fruits produce greater amounts of ethylene than immature and semi-mature fruits. Cultivar, storage time, temperature, and fruit maturity also influence ethylene production and respiration. The effect of ethylene on fruit correlates with climacteric respiration and changes in membrane parameters, including loss of phospholipids and increased membrane permeability. On the other hand, previous results have shown that respiration has an indirect effect on the peroxidation of lipid cell membranes through the formation of active oxygen species (AOS) during respiration processes, resulting in oxidative stress. Increased malondialdehyde (MDA), indicating increased membrane damage, has also been observed. Respiratory rate is suppressed by temperature and gas composition, although the mechanism of respiratory suppression by lowering mango oxygen (O2) levels is currently unclear. This is due to the rapid breakdown of carbohydrates and organic compounds by various chemicals and enzymes at high temperatures. Post-harvest quality?losses Major postharvest quality losses of mangoes occur at different stages of the supply chain. Quality loss is influenced by harvesting fruit at inappropriate maturity, inadequate field handling, use of improper transportation, mechanical damage caused during harvest or improper field handling, bruising, sap burn, rapid ripening, spongy tissue, lenticel discoloration, decay, chilling injury, disease and pest damage, and some other disorders. Mangoes are perishable, especially if the fruit is damaged, stored at ambient conditions or at low temperatures of 7?13?C, resulting in chilling injury. Especially considering that mangoes are produced on a large scale in developing countries around the world. Symptoms of chilling injury include skin pitting, sunken skin lesions, uneven ripening, poor flavor and increased susceptibility to rot. Postharvest diseases reduce fruit quality and result in significant losses. Mango fruit is exposed to postharvest decay through wounds infected with pathogens that cause anthracnose (Colletotrichum gloeosporioides), alternaria black spot (Alternaria alternate), and stem end rot (Lasiodiplodia theobromae or Dothiorella dominicana or Botryosphaeria spp), compromising fruit quality throughout the supply chain. Postharvest pests also reduce their quality. Mango is one of the fruits reported to be host to several fruit flies such as the Mediterranean fruit fly (Ceratitis capitata), Mexican fruit fly (Anastrepha spp.) and Queensland fruit fly (Bactrocera tryoni), which are considered to be a quarantine risk in many importing countries. In Closing The mango is a vital tropical fruit that is harvested green and then ripened to achieve the desired flavor and texture. However, the perishable nature of the fruit causes significant post-harvest losses. It is crucial to understand the physiological changes during the ripening process to maintain the quality, nutritional content, and market value of the fruit. The article discusses the importance of the maturity of the fruit at harvest, which determines the quality and shelf life. During ripening, there are large changes in physiological, biochemical, and organoleptic properties. Ethylene triggers changes like flesh color, chlorophyll degradation, accumulation of carotenoid content, firmness decrease, and juiciness increase. Quality losses occur at different stages of the supply chain due to various factors like inadequate field handling, mechanical damage, chilling injury, postharvest diseases, and pest damage. Understanding the physiology of mango ripening can reduce these losses and ensure a good quality product throughout the supply chain. Author:?Jorge Luis?Alonso G. (with ChatGPT)?Maximizing Agribusiness Profits with Expert Postharvest Storage Strategies | Horticultural Writing Specialist.?This article was written exclusively for the business platform Postharvest. Cover photo: Pixabay.