2018 ASHS Annual Conference

In 'Tommy Atkins’, it is common to find a high percentage of fruit with 'shrunken shoulders'. The objectives of this work were to study if fruit ripening degree, quarantine hot water treatment (QHWT), hydrocooling, rest after hydrocooling, and nutritional status of the orchard influence this anomaly in ‘Tommy Atkins’ fruit. The study was conducted during the 2017 season with fruit harvested in Jalisco, Nayarit and Sinaloa. Treatments included: 1) Origin; 2) Ripening degree (partial ripe and ripe); 3) Time of QHWT (75 or 90 min); 4) Hydrocooling (immediate, after 30 min and without), and 5) Rest (without or rest for 24 h). Once the treatments were applied, fruit were stored for seven days in refrigeration (53.6 ± 1.5 °F; 95 ± 5 % RH) and then under marketing simulation (71.6 ± 3 °F; 75 ± 10 % RH) until consumption stage. Sampling was done at the beginning and end of the refrigerated storage and at consumption stage. Variables measured were percentage of shrunken shoulders, weight loss, firmness, pulp color, and total soluble solids content. A completely randomized design with a factorial arrangement was used. Results showed almost 30 % of fruit with shrunken shoulders. Fruit harvested in Jalisco did not show the damage whereas fruit from Nayarit and Sinaloa had 27.1 and 28.3 % damage, respectively. The factors that most influenced presence of shrunken shoulders symptoms were ripening degree at harvest and rest. Fruit harvested partially ripe showed a higher percentage of this anomaly in all the samplings. At the beginning, the partially ripe fruit showed 18.1 % of fruit with shrunken shoulders, as compared to only 3.9 % of the ripened fruit. At the end of refrigeration, partially ripe fruit increased shrunken shoulders symptoms to 25.3 %, while ripened fruit showed only 8.9 %. At consumption stage, the partially ripe fruit had 25.6 % of fruit with symptoms, while ripe fruit only 11.4 %. The other factor that significantly influenced the presence of fruit with shrunken shoulders was the rest, mainly in the initial sampling, where the fruit with rest of 24 h showed three times more fruit with symptoms (16.1 %) than those without rest (5.8 %). In conclusion, to reduce or avoid the incidence of fruit with shrunken shoulders, it is recommended to harvest ripe fruit, as well as to avoid a rest period of 24 or 48 h traditionally carried out by the packers.