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- Author or Editor: Susan B. Jones x
Fruits from thornless blackberry (Rubus sp.) cultivars were compared to determine causes of variation in drip losses during thawing after frozen storage. Drip was similar in composition to juice obtained by pressing. Drip losses for different cultivars ranged between 1% and 30% in 1984; increased losses in 1983 were attributed to poor fruit condition (e.g., deterioration during postharvest holding). Drip losses were greater in riper samples but did not depend on fruit size. Drip losses were correlated with low insoluble pectin. Microscopic examination revealed an inverse relationship between the tendency to drip and the epidermal cell layer thickness.
The effect of cultivar on cranberry (Vaccinium macrocarpon Ait.) fruit size and composition was investigated. ‘Ben Lear’, ‘Crowley’, ‘Early Black’, and ‘Franklin’ berries contained about twice the anthocyanin of the other clones. Based on projections of analytical data, potential gain could be enhanced by increasing the proportion of berries that attain high anthocyanin content, seen in individual fruits within samples, as compared to the alternative strategies of breeding for improved anthocyanin content, for small berries, or for synchronous ripening.
The anthocyanin content of ripe berry samples of 11 cultivars of highbush blueberry (Vaccinium corymbosurn L.) varied over a 3-fold range. HPLC separation of individual anthocyanins in blueberry samples revealed 3 distinct anthocyanin patterns. Visible absorption spectra of aqueous berry extracts reflected differences in anthocyanin concentration and pH, the latter especially being evident with the more acidic berries of ‘Coville’ and ‘Elliott’. Tristimulus reflectance measurements made on whole berries correlated with visual assessment of waxy bloom but not with anthocyanin content, anthocyanin pattern, or juice pH. SEM examination revealed 2 different surface structures in samples exhibiting bloom. Tristimulus parameters for blueberry juice were dependent on anthocyanin concentration, pH, and the occurrence of browning, but not on the pattern of individual anthocyanins.
Marketed as a fresh fruit, the pawpaw (Asimina triloba) has a short shelf life, only 2-3 days at room temperature and up to 3 weeks with refrigeration. There is commercial processing potential for pawpaw pulp in juices, ice cream, yogurt, baked goods, and other products. Consumer acceptability of such products needs to be investigated. One hundred and five attendees of the 2nd Annual Pawpaw Field Day at Kentucky State University (KSU), Frankfort, Ky., participated in a tasting of pawpaw products; 56% of tasters were male; 76% were over 40 years of age; 72% of tasters had eaten pawpaw previously. Each item was rated on a scale from 1 = liked it extremely to 7 = disliked it extremely. Pawpaw ice cream was the best-received item (55% of tasters liked it extremely), followed by pawpaw cake with lemon icing, liked extremely by 45%. The pawpaw/grape juice drink was liked extremely by 31% of participants. Three alternative recipes for pawpaw butter were presented; the plain pawpaw butter was liked extremely by 26% of tasters; pawpaw butter prepared with lemon and grape juice was liked extremely by 11%, while the version prepared with orange and lemon was liked extremely by only 8%. Two versions of pawpaw custard were presented. The custard prepared from ripe, mild-fl avored fruit was liked extremely by 42% of tasters, while the custard prepared from mixed under-ripe, over-ripe and bruised fruit was liked extremely by only 16%. Ratings by persons unfamiliar with pawpaw fl avor were significantly lower (P < 0.05) only for the two pawpaw custards; tasters age 40 years or younger gave significantly higher ratings for pawpaw ice cream (P < 0.05) and significantly lower ratings for both pawpaw custards (select, P < 0.05 and mix, P < 0.01) and the pawpaw/grape juice drink (P < 0.05).
Spraying with 3% ethyl oleate (EO) reduced the incidence of cracking from 29 to 11% in ‘Vista’ cherries (Prunis avium L.) Applications of EO increased the rate of dehydration in cherries exposed to ambient air following treatment. Scanning electron microscopy (SEM) observations suggest that EO modifies the cherry cuticle by redistributing surface wax, thereby enhancing mass transfer of water vapor through the skin.
Baked ceramic aggregates (fritted clay, arcillite) have been used for plant research both on the ground and in microgravity. Optimal control of water and air within the root zone in any gravity environment depends on physical and hydraulic properties of the aggregate, which were evaluated for 0.25-1-mm and 1-2-mm particle size distributions. The maximum bulk densities obtained by any packing technique were 0.68 and 0.64 g·cm-3 for 0.25-1-mm and 1-2-mm particles, respectively. Wettable porosity obtained by infiltration with water was ≈65%, substantially lower than total porosity of ≈74%. Aggregate of both particle sizes exhibited a bimodal pore size distribution consisting of inter-aggregate macropores and intra-aggregate micropores, with the transition from macro- to microporosity beginning at volumetric water content of ≈36% to 39%. For inter-aggregate water contents that support optimal plant growth there is 45% change in water content that occurs over a relatively small matric suction range of 0-20 cm H2O for 0.25-1-mm and 0 to -10 cm H2O for 1-2-mm aggregate. Hysteresis is substantial between draining and wetting aggregate, which results in as much as a ≈10% to 20% difference in volumetric water content for a given matric potential. Hydraulic conductivity was approximately an order of magnitude higher for 1-2-mm than for 0.25-1-mm aggregate until significant drainage of the inter-aggregate pore space occurred. The large change in water content for a relatively small change in matric potential suggests that significant differences in water retention may be observed in microgravity as compared to earth.