Use of Maturity Indices for Predicting Poststorage Firmness of `Fuji' Apples

Abstract

<jats:p>`Fuji' apples (<jats:italic>Malus domestica</jats:italic> Borkh.) were harvested at three maturities for three consecutive seasons. Fruit firmness, soluble solids concentration, starch—iodine index (SI), and internal ethylene concentration were measured at harvest. Fruit were stored in 0 °C air storage for 8 months. Fruit firmness and other maturity indices were measured monthly during storage. Using a stepwise regression procedure, harvest maturity indices were used to predict firmness after air storage. When all maturity indices measured were represented in the model, <jats:italic>R</jats:italic><jats:sup>2</jats:sup> = 0.29, 0.34, and 0.26 at 4, 6, and 8 months, respectively. Use of only SI and fruit firmness in the model gave <jats:italic>R</jats:italic><jats:sup>2</jats:sup> values of 0.25, 0.29, and 0.24 for 4, 6, and 8 months, respectively. Although <jats:italic>R</jats:italic><jats:sup>2</jats:sup> values were low, they were highly significant. The model using fruit firmness and SI resulted in the best fit. Thus, an equation was developed using months of air storage, firmness, and SI at harvest. Actual firmness values correlated fairly well with predicted firmness values, usually within ≈5 N. On Washington apples, predicted values were 4.3 and 3.7 N too low compared to actual firmness values after 3 or 5 months' storage. In 1993, when predicted and actual firmness values were compared for Pennsylvania apples, predicted values ranged from 2.6 to 8.3 N too high after 3 months' storage, depending on harvest date. In 1994, Pennsylvania fruit stored 4 months had predicted values 0.5 N too high to 6.3 N too low, depending on harvest date. It may be possible to develop and refine models for an apple variety that would be applicable to several regions.</jats:p>

Fruit dry matter concentration: a new quality metric for apples

“…The advantage of the latter approach is that it provides early insights for logistics and marketing and can help to identify physiological processes and crop management practices that can be modified in order to provide solutions that improve quality across an entire fruit sector. Traditionally, the best examples of the biologically based quality standards involve the monitoring of fruit maturity to support decisions on the timing of harvest 14–16…”

Post-harvest physico-mechanical properties of orange peel and fruit

“…The properties such as color and firmness of orange that differentiate individual units of a product are important to determine the degree of acceptability of the product to the buyer (Guzel, Alizade, & Sinn, 1994). Fruit softening is often used as a criterion for estimating the feasibility of their storage or shelf life (Kader, 1992;Polderdijk, Tijskens, Robberts, & Van der Valk, 1993;Blankenship, Parker, & Unrath, 1997).…”

Optimal sampling strategies for evaluating fruit softening after harvest in apple breeding

“…Since apples are not always marketed directly after harvest (Kingston, 1992), growers and markets are quite concerned about the length of time that fruit retains its firmness, which is directly linked to consumer acceptance. Many studies, consequently, have attempted to predict changes in fruit firmness from harvest to after or during storage using regression equations by measuring quality at harvest (Ingle et al, 2000;Johnson & Ridout, 1998;Blankenship et al, 1997;Evensen et al, 1993;Ingle & Morris, 1989) or to determine harvest indicators that have a close relationship to firmness after storage (Ingle & D'Souza, 1989;Knee & Smith, 1989).…”