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  • Author or Editor: G. M Sapers x
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Abstract

Fifty-eight cultivars of tomatoes were screened for the occurrence of high pH fruit. Although large differences in pH were found between and within cultivars, no pH values high enough to permit the growth of Clostridium botulinum were obtained. pH and titratable acidity were not highly correlated. Tomato acidity data obtained from 57 locations in 23 states for 356 cultivars and 212 breeding lines were compiled and analyzed to identify trends. These data show that small-fruited, light colored and “new” cultivars are not low in acid, as is commonly believed. A few high pH data points (pH ⩾ 4.7) were associated with specific cultivars, locations, and conditions (overripening). The response of some higher pH cultivars to acidulation with citric acid was determined; a linear relationship between pH and added acid was found. These data were used to evaluate several methods of acidulation recommended for home canners.

Open Access

Abstract

In the paper “Factors Affecting the Recovery of Juice and Anthocyanin from Cranberries” by G.M. Sapers, S.B. Jones, and G.T. Maher [J. Amer. Soc. Hort. Sci. 108(2):246–249, 1983], there is an error in the magnification in the Fig. 1 legend. The correct version of the legend is as follows:

Open Access

Abstract

Factors affecting anthocyanin recovery in juice from pressed cranberries (Vaccinium macrocarpon Ait.) were investigated under laboratory conditions. Anthocyanin recovery was unaffected by cultivar, total anthocyanin content, or juice yield. Variability in anthocyanin recovery was attributed to the heterogeneity of berry samples analyzed for total and juice anthocyanin and to differences in the efficiency of pigment extraction by juice liberated during pressing. Freeze-thaw treatment of cranberries increased juice yield by as much as 50% and juice anthocyanin content by as much as 15-fold. Microscopic observation of changes at the cellular level resulting from freeze-thaw treatment supported the juice yield and pigment recovery data. Anthocyanin recovery could be increased by double pressing and by tissue homogenization.

Open Access

Abstract

Increases in the darkness and redness of both thawed and cooked highbush blueberries (Vaccinium corymbosum L.), indicated by tristimulus measurements, were cultivar-related but not dependent on blueberry pH or anthocyanin content. Waxy bloom was retained in thawed berries but lost during cooking. Pigmented exudate appeared with some cultivars during thawing. Differences among cultivars in exudate formation and reddening during thawing are explained in terms of changes in epidermal cells, cuticle, and wax structure which were observed by light and electron microscopy. The color of blueberry cooking water depended primarily on the berry anthocyanin content, acidity, and the extent of leaching.

Open Access

Abstract

Samples of 45 cranberry clones (Vaccinium macrocarpon Ait.) were analyzed for factors relating to fruit quality and processability to develop selection procedures for breeding programs. High correlations were obtained between tristimulus reflectance measurements on whole or pureed cranberries and the juice color, determined by spectrophotometric or tristimulus transmission measurements. Differences between cranberry samples in the proportions of individual anthocyanins were small and not correlated with berry or juice color. A 3-stage sequence of simple measurements, entailing minimal sample preparation, was developed for selection. First- and second-stage selections were based on the application of discriminant analysis to tristimulus reflectance data obtained with whole and pureed cranberry samples, respectively. In the third stage, selections were based on analytical measurements performed on juice prepared from samples selected in the preceeding stages.

Open Access

Abstract

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.

Open Access

Abstract

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.

Open Access

Abstract

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.

Open Access

Abstract

Ripe fruit of 40 thornless blackberry cultivars and selections, and juice samples obtained therefrom, were compared to determine differences in color and composition after freezing, thawing, and heating. Color changes (reddening) during frozen storage were associated with within-sample variability in ripeness. Red subsamples of frozen blackberries were lower than black subsamples in soluble solids and total anthocyanin contents and higher in titratable acidity and anthocyanin recovery in the pressed juice. When juice samples were standardized to compensate for differences in pH and anthocyanin concentration, ripeness and cultivar effects on juice tristimulus parameters were small. Rapid thawing of frozen fruit resulted in less anthocyanin loss than did slow thawing. Heating darkened blackberry juice samples and increased values of A440/A513.

Open Access

Abstract

Samples of 16 cranberry (Vaccinium macrocarpon Ait.) clones, sorted into subsamples on the basis of berry size and coloration, were analyzed for juice content, soluble solids, titratable acidity, and anthocyanin content. The soluble solids : acidity ratio was greater for more highly colored subsamples but did not vary with berry size. The anthocyanin content of subsamples of different berry size varied in proportion to the surface to volume ratio. Anthocyanin recovery in expressed juice was independent of berry coloration and size. Variability in anthocyanin content within samples reflected differences in environmental factors, such as light exposure, superimposed on ripeness differences. Variability in sample anthocyanin content depended more on berry size differences than on differences in surface coloration.

Open Access