Nonvolatile acids, sugars, and aroma volatiles from Majestic peaches were measured during maturation from 54 to 126 days after flowering. The highest levels of sucrose, lowest quinic acid levels, and second maximum malic/citric acid ratio occurred when mesocarp dry matter and seed reached their highest weight. Linalool, benzaldehyde, -decalactone, and -decalactone increased significantly during the final stages of maturation with -decalactone being the principal volatile compound. The increased levels of volatiles also closely paralleled seed and mesocarp growth. Pit lignification was complete about 50 days before the seed and mesocarp fully developed. Sucrose, quinic acid, malic/citric acid ratio, and major volatiles either singly or in combination appear to be useful indices for determining physiological maturity in the mesocarp and seed of Majestic peaches.

Phenolic acids were extracted from the nutmeats and/or testae of pine nut, almond, filbert, American Chestnut, a hybrid American chestnut, Chinese chestnut, black walnut, butternut and shagbark hickory and analyzed as their methyl esters/trimethylsilyl derivatives by GLC-MS. Both qualitative and quantitative differences were observed among samples in the acids present with gallic acid being predominant except in pine nut, almond and filbert. Caffeic was the predominant acid in pine nut; protocatechuic acid was predominant in almond and filbert. Phenolic acids isolated and identified were p-hydroxybenzoic, p-hydroxyphenylacetic, vanillic, protocatechuic, syringic, gallic, caffeic and ferulic acids.

Permittivities, moisture contents, tissue densities, and total soluble solids data were determined for samples of twenty-three kinds of fresh fruits and vegetables at 23 degrees C. Permittivities were measured at 41 frequencies between 200 MHz and 20 GHz with an open-ended coaxial-line probe and a microwave network analyzer. Results of the permittivity measurements are presented graphically, and dielectric constant and loss factor values at six frequencies across the range are tabulated along with sample descriptions and moisture, density, and total soluble solids data. Although specific values differ, the dielectric constant decreases steadily with increasing frequency, dropping more rapidly at frequencies above 5 GHz. Values for the loss factor decrease as frequency increases above 200 MHz to a broad minimum in the 1- to 3-GHz region and then increase again as the frequency approaches 20 GHz. The dielectric behavior of the fruit and vegetable tissues appears to be influenced by ionic conductivity and bound water relaxations at the lower frequencies and by free water relaxation at the higher end of the frequency range.

Sugars and nonvolatile acids of Japanese persimmons were identified and quantitated by GLC as oxime-TMS derivatives. Sugars quantitated were arabinose, galactose, glucose, fructose and sucrose. Fructose, glucose and sucrose were predominant and present in all cultivars from mature green to fully ripe. Quantities of all sugars varied significantly by cultivar and maturity. Nonvolatile acids quantitated were succinic, malic, citric, and quinic. Malic was the predominant acid in all cultivars followed by citric. Quantities of malic increased with maturity; citric decreased. Sorbitol and inositol were present in minor quantities and varied significantly by cultivar and maturity stage.

Changes in the physical, chemical and sensory characteristics of peaches (cv. 'Majestic') were determined. Size, weight, ground color "a" values and SSITA ratio increased sign$cantly with increased degree of maturity; whereas, j r mness, DLE, hue angle, titratable acidity, quinic acid, and citric acid decreased signifcantly. Malic acid increased signijicantly with maturity up to grade 5 then signifcantly decreased. In general sucrose content and total sugars increased through grade 6 and then decreased for tree ripe fruit. Sensory evaluation results showed no signifcant differences among maturity grades for sweet, sour, juice and overall peach flavor attributes. However, grade 1 and 2 fruit had lower scores for sweet and overall peach flavor attributes and tended to be more sour than grades 3-6 and tree ripe fruit. Correlation coeflcients between maturity grade and all the selected quality parameters, except for the sourjavor attribute, were significant at the I% level. DLE had the highest correlation with maturity grade followed by ground color "a" value, SSITA ratio andjrmness.