Author
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OSUNA-GARCIA, JORGE - INSTITUTO NACIONAL DE INVESTIGACIONES FORESTALES Y AGROPECUARIAS (INIFAP) |
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NOLASCO-GONZALEZ, YOLANDA - INSTITUTO NACIONAL DE INVESTIGACIONES FORESTALES Y AGROPECUARIAS (INIFAP) |
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Goenaga, Ricardo |
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Submitted to: Meeting Abstract
Publication Type: Abstract Only Publication Acceptance Date: 7/11/2018 Publication Date: 8/3/2018 Citation: Osuna-Garcia, J.A., Nolasco-Gonzalez, Y., Goenaga, R.J. 2018. Cause of shrunken shoulders in ‘Tommy Atkins’ fruit grown in diverse production areas in Mexico. Meeting Abstract. Abstract. Interpretive Summary: Technical Abstract: In 'Tommy Atkins’ mango, it is common to find a high percentage of fruit with 'shrunken shoulders‘, which can be caused by several factors and render the fruit non-commercial. Packers note that partially ripe fruit is more susceptible to present this problem. During the last few seasons this anomaly has been present in ripe fruit harvested in certain production areas in Mexico. It has been reported that this disorder can be present in unripe mango fruit subjected to quarantine hot water treatment (QHWT) or that has exceeded time or recommended temperature under QHWT. Hydrocooling immediately after QHWT is recommended because it reduces pulp temperature faster than just leaving the fruit at room temperature, which in turn prevents some of the possible injury caused by QHWT. Concerning resting period after QHWT and/or hydrocooling, packers argue that waiting for 24 to 48 hours before classification and packing is very useful to detect fruit with shrunken shoulders. Finally, it seems that nutritional conditions influence the presence or absence of shrunken shoulders. The objectives of this work were to study if fruit ripening degree, QHWT, hydrocooling, resting period after hydrocooling, and nutritional status of the orchard influence the incidence of shrunken shoulder in ‘Tommy Atkins’ fruit. The study was conducted during the 2017 season with fruit harvested in Jalisco, Nayarit and Sinaloa states, Mexico. Treatments included: 1) Production site; 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) Resting period (without or fruit resting for 24 h). Once the treatments were applied, fruit were stored for seven days under refrigeration (53.6 ± 1.5 °F; 90 ± 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 the 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 disorder, 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 resting period. Fruit harvested partially ripe showed a statistically higher percentage of this anomaly in all the samplings. At the end of refrigeration, partially ripe fruit increased shrunken shoulders incidence to 25.3 %, while ripe 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 %. Another factor that significantly influenced the presence of fruit with shrunken shoulders was the resting period, mainly in the initial sampling, where the fruit with resting period of 24 h showed three times more fruit with symptoms (16.1 %) than those without rest (5.8 %). To reduce or avoid the incidence of fruit with shrunken shoulders, it is recommended to harvest ripe fruit, as well as to avoid a resting period of 24 to 48 hours as traditionally carried out by the packers. |
