Mango (Mangifera indica L) is a climacteric tropical fruit that has become popular around the world. US is the largest imported of mango in America, importing mangos from Mexico, Guatemala, Peru, Ecuador, Brazil, Haiti, and Puerto Rico. Mangos most often spend several days (15 to 36) in transit from their country of production to the wholesale markets in the US. Upon arrival at the East Coast (Philadelphia) and West Coast (Los Angeles), mangos are transferred to distribution centers prior to retail stores. Presently 85 to 90 % of imported mangos to the US receive a hot water treatment (HWT) to control Mediterranean and Mexican fruit fly since late 1980s (USDA-APHIS-PPQ, 2022). There are limited postharvest studies of imported mangos to the US available and most of them were carried out using non hot water treated (NHWT) mangos. Over the years, US Mango consumption has increased from 1.7 to 3.6 pounds per capita during the last two decades based on HWT contribution. However, the US mango per capita consumption is still lower than other commodities available in similar yearly cycle. In 2020, bananas, apples, pineapples, and table grapes had a 27.4, 17.6, 7.3, and 8.4 per capita respectively. We believe that for imported mangos to compete with the wide variety of fruits and vegetables available to purchase and satisfy consumers, a clear understanding on consumer quality and postharvest quality deterioration at arrival and distribution in the US is important to propose postharvest handling strategies during transportation, distribution centers, retail stores and consumer education.As a first step of our work, we surveyed mango quality at arrival to stores across US for one season. Based on these results, we hypothesized that the main barriers to increase US mango consumption further were chilling injury incidence, consumer sensory quality, softening problems, low availability of high flavor ‘ready to eat’, and lack of handlers-consumer education. Therefore, two studies were developed following our previous assessment of arriving quality of HWT mangos imported to the US. These chapters deal with modifications of the current ‘ready to eat’ ripening protocol (Testing the Performance of Exogenous Ethylene Application on Ripening of Hot Water Treated Imported Mangos (Mangifera indica, L.) – Chapter 1) and Understanding the Role of the Physiological Maturity and Shipping Temperature on HWT Mango Arrival Quality (market life potential-chilling injury– Chapter 2). Our results, working with HWT mangos, revealed current potential mango limitations and pointed out at which step(s) during handling quality, problems were occurring. This new information allows assisting postharvest handling changes and establishing strong educational programs to reduce these problems and increase US mango consumption.
Chapter 1 Exogenous ethylene gas treatment is part of the ripening protocol to deliver ‘ready to eat’ mangos that satisfies consumers preferences and increase mango consumption in the US. In the first chapter, the hypothesis stated that ethylene effectiveness would vary depending on the maturity ripening category of HWT mangos at arrival because mature mangos were already producing ethylene or being exposed to exogenous ethylene from other mangos during handling and transportation to market area. The performance of ethylene was assessed in three batches of ‘Tommy Atkins’ mango, one batch of ‘Ataulfo’, one batch of ‘Keitt’ mangos, all from Mexico, and a batch of ‘Kent’ mango from Peru. All mangos were treated with hot water expect for ‘Keitt’ that came from a fruit fly free zone. Data collected during this study supported the hypothesis and suggested that exogenous ethylene treatment is not necessary to achieve the ‘ready to eat’ stage for HWT mangos. Furthermore, ethylene treatments add handling, cost and delays to the mango postharvest chain that can result in lower fruit quality due to physical damage.
The second chapter was a study in cooperation with CIAD (Culiacan, MX) to find the major defects that impact quality of hot water treated mangos due to low temperature, and temperature exposure during shipment or storage. ‘Tommy Atkins’, ‘Kent’, and ‘Ataulfo’ mangos were collected from a packinghouse in Escuinapa, Culiacan, Mexico. They were classified into three harvest maturity stages using a non-destructive DA meter, and evaluating shape, skin color, shoulder shape, shoulder location in relation to peduncle insertion and skin texture. Quality was assessed at harvest and during cold storage; the initial destructive quality measurements include flesh firmness, flesh color, soluble solids concentration (SSC), and dry matter percentage. Cold storage evaluation was conducted on ripe mangos and assessed external chilling injury (CI) symptoms such as lenticel discoloration, skin pitting, grayish scald, and surface scald. Internal decay was also part of this evaluation and included loss of flesh color, and in severe cases flesh browning. Our results highlighted skin discoloration and fast softening during transportation as the main barriers to deliver high quality mangos at arrival after 30 days.