Abbreviations: SSC, soluble solids content; TA, titratable acid content. The cost of publishing this paper was defrayed in part by the payment of page charges. Under postal regulations, this paper therefore must be hereby marked advertisement
Storage of `McIntosh' apples (Malus domestica Borkh.) in high humidity (94% to 100% RH) or in 0.5% CO2 plus 1.0% O2 at 3C (LO) atmospheres decreased resistance to ethane diffusion relative to fruit stored in low humidity (75% RH) or in 5.0% CO2 plus 3.0% O2 at 3C (SCA), respectively. Loss of fruit firmness of SCA- or LO-stored `McIntosh' apples, determined immediately after storage or after 7 days at 20C, decreased with increased storage humidity in each of three crop years. Storage humidity did not significantly affect (P = 0.05) fruit titratable acids or soluble solids contents. High storage humidity (96% to 100% RH) generally increased the incidence of senescent disorders (consisting of senescent breakdown and senile brown core) in SCA-stored fruit, while humidities of 92% to 100% RH decreased the incidence of low-O2 injuries (epidermal bluing and cortical browning) in LO-stored fruit. Senescent disorders were found in SCA-stored fruit, but not in LO-stored fruit. The incidence of decay was not significantly affected by either storage humidity or atmosphere.
Kevin M. Keener, Richard L. Stroshine, and John A. Nyenhuis
A 5.40-MHz NMR system was used for measuring the self-diffusion coefficient of water (Dw) and the spin-spin relaxation constant (T2) in apple (Malus ×domestica Borkh.) tissue. The pulsed field gradient spin echo (PFGSE) technique was used to measure Dw, and the Carr-Purcell-Meiboom-Gill (CPMG) technique was used to measure T2. T2 and Dw values were compared for apples with differing amounts of soluble solids concentration (SSC) and with and without internal defects, such as bruising, watercore, and internal browning. `Granny Smith', `Golden Delicious', and `Delicious' apples were tested. In `Golden Delicious', Dw highly correlated with apple tissue SSC (P < 0.002, r 2 = 0.68). This indicates that Dw could potentially be used for sorting `Golden Delicious” apples based on SSC, but the coefficient of determination needs to be improved before it would be commercially viable. There were no measurable differences in Dw among healthy apple tissue and tissue affected by either watercore or internal browning. T2 values showed no relationship between healthy apple tissue and bruised tissue in `Golden Delicious' and `Granny Smith'. However, in `Delicious' tissue, T2 values were statistically different between healthy and bruised tissue (P < 0.02). Further comparisons in `Delicious' between watercore and healthy apple tissue showed no differences. But, there were statistical differences found between T2 in healthy apple tissue and tissue with internal browning (P < 0.01). These results indicate that T2 could potentially be used for separating `Delicious' apples with internal browning or with bruising from healthy apples. Titratable acids and pH were correlated for `Golden Delicious' (P < 0.08). This correlation is significant because one may be able to noninvasively measure pH in `Golden Delicious' apples using NMR, which could then be correlated to titratable acids.
Jennifer R. DeEll and Robert K. Prange
Postharvest quality and sensory attributes of organically and conventionally grown `McIntosh' and `Cortland' apples (Malus domestica Borkh.) stored at 3C in ambient air or in controlled atmospheres were evaluated. Organically grown apples had higher soluble solids concentration than conventionally grown apples, while there were no significant differences in firmness or titratable acids content. Organically grown `McIntosh' were perceived by sensory panelists as firmer than conventionally grown `McIntosh' at harvest but not after storage, which may have been due to maturity differences. No significant differences were perceived in juiciness, sweetness, tartness, and off-flavor of apples at harvest or after storage.
Paul M. Chen and Diane M. Varga
`D'Anjou' pears (Pyrus communis L.) harvested at commercial maturity and stored in air at 30 °F (-1 °C) for up to 7 weeks were still incapable of ripening normally at 68 °F (20 °C) for 7 days. `D'Anjou' fruit at this stage were termed as under-chilled fruit. Ziploc bags [1-gal (3.8-L)] perforated with a number of small holes [1/8 inches (0.32 cm) in diameter] were used to pack five `d'Anjou' pears and five `Bartlett' pears [a total net weight of 5 ± 0.2 lb (2.3 ± 0.1 kg)]. The mixed fruit packed in the same bags were placed into a room at 68 °F. When under-chilled `d'Anjou' fruit packed with `Bartlett' fruit in the bags perforated with 6, 8, or 10 holes, `Bartlett' fruit became fully ripe after 5 days while `d'Anjou' fruit were capable of ripening normally after 7 days at 68 °F. Ripened fruit of both pear cultivars developed high dessert quality. The concentration of ethylene in these bags accumulated to ≈50 ppm (mg·L-1) on day 4 while CO2 concentration did not increase to above 3% and O2 concentration maintained at 18%. Ethylene generated naturally by `Bartlett' pears during ripening at 68 °F and accumulated in the bag perforated with 6 to 10 holes was sufficient to induce the normal ripening activities of under-chilled `d'Anjou' pears. This packaging technology may be used to promote early marketing for both pear cultivars.
Paul M. Chen, Diane M. Varga, and Clark F. Seavert
We have established that `d'Anjou' pears (Pyrus communis) are properly ripened for fresh-cut use when flesh firmness (FF) is between 5 lb (2.3 kg) and 7 lb (3.2 kg). In this study, the fruit was ripened in air enriched with 100 ppm (mL·L-1) ethylene at 68 °F (20.0 °C). Afterward, we investigated three slicing methods, each employing a fruit sectionizer for dividing individual pears into eight wedges. The easiest and most convenient cutting procedure involved pouring an antibrowning agent onto the incision, but without allowing the fruit to directly contact the air. We evaluated various combinations of L-ascorbic acid (vitamin C) and potassium chloride (KCl) for their ability to prevent any discoloration while also not affecting taste or injuring the cut surface. The most suitable antibrowning solution contained 10% L-ascorbic acid and 2% KCl (pH 2.3). A dipping time of 30 s was sufficient for maintaining the wedges with little discoloration over a 14-d period, at either 30 or 35 °F (-1.1 or 1.7 °C). Here, we also present a prototype design for a 1.6-pt (0.76-L) transparent plastic container with eight compartments for holding wedges sliced with a commercially available sectionizer.
Meng-Shiun Tsai, Tan-Cha Lee, and Pai-Tsang Chang
color. Juice percentage, total soluble solid, and titratable acid. Fruit pulps from the second group were recorded (grams/fruit) and then homogenized in a blender and filtrated to collect juice weight (grams/fruit). The juice percentage was calculated as
Guang-Lian Liao, Xiao-Biao Xu, Qing Liu, Min Zhong, Chun-Hui Huang, Dong-Feng Jia, and Xue-Yan Qu
of the chromameter was D65). The concentrations of soluble sugars, titratable acids, pigment, and ascorbic acid concentrations were measured after the fruit pulp was ground in liquid nitrogen ( Liao et al., 2019b ). Data analysis The experimental data
Julia M. Harshman, Wayne M. Jurick II, Kim S. Lewers, Shiow Y. Wang, and Christopher S. Walsh
flavor, appearance, and nutritive value of red raspberries ( Kruger et al., 2011 ). Soluble solids increase in storage, which causes the fruit to taste sweeter, whereas titratable acids decrease in storage making the berries taste more dull and flat
Ying Wang, Tingting Xue, Xing Han, Lingxiao Guan, Liang Zhang, Hua Wang, and Hua Li
weight, soluble solids (SS), reducing sugar (RS), and titratable acid (TA). The remaining berries were stored at −80 °C until later analysis. The physicochemical indexes of grape berries. A subsample of 50 grapes was randomly collected from different