S Dimethyl sulfide (DMS) was the most abundant aroma volatile in cooked sweet corn head‐space, followed by ethanol, acetaldehyde, hydrogen sulfide (H2S), ethanethiol, methanethiol and another unidentified compound unique to processed corn. Based on sensory monitoring of GC column effluents, DMS was determined as the primary factor in cooked corn aroma along with H2S, methanethiol and, to a lesser degree, ethanethiol. Also detected in the effluents, but probably of lesser importance, were acetaldehyde, ethanol, and a “grainy” smelling compound in processed corn. When panelists were asked to score corn of widely varying characteristics for aroma, sweetness, texture and overall flavor, it was found that aroma contributed 15% to the flavor response while sweetness and texture contributed 55% and 30%, respectively.

In order to assess the effects of heat, cultivar and maturity upon muscadine grape anthocyanins (Acys), the Acys were extracted from heated muscadine juices, from 11 cultivars of muscadines, and from muscadines separated into levels of maturity. Individual Acys were separated by thin-layer chromatography (TLC) and quantitated by densitometry. Heating resulted in relative increases in the 3,5-diglucosides of cyanidin (Cy), malvidin (Mv) and peonidin (Pn) at the sacrifice of delphinidin (Dp) and petunidin (Pt)-3,5-diglucosides. Except for an initial sharp loss of Mv, Dp degraded most rapidly with heating followed by Pt, Cy, Mv, and Pn. Total Acys in the 11 cultivars ranged from 40 to 403 mg/lOOg fruit with wide variations in the relative contents of individual Acys. Dp was usually the most prevalent Acy in the pigment complex followed by Cy or Pt, Pn and Mv. Cultivars with relatively high Mv and total Acys contents yielded juices and jellies with the highest quality and most stable colors. Harvest date influenced relative percentages of Pn, Mv, and Dp. Maturity level influenced the relative percentage of Mv and concentrations of all Acys.

Cold -and hot-pressed

Nine black cultivars of muscadine grapes and four bronze cultivars were evaluated for their processing potential for juices and jellies. After harvesting the grapes by a method simulating mechanical harvesting, they were washed, sorted, crushed and deseeded, and the juice pressed out. Records were kept on percent ripe fruit, size, stem scarring, seed and skin contents, processing losses, and juice yields for each cultivar. Quality evaluations of the juices and jellies prepared from the grapes included soluble solids, titratable acidity, tannin, color measurement, and color and flavor scores. The flavor of cold-press juices was preferred over hot-press juices. The color of processed products from black cultivars was preferred to those from bronze cultivars, while bronze grape products had a slight flavor preference. Browning occurred rapidly in cold-press red juices stored at room temperature. There were wide variations in the processing properties and quality characteristics of the 13 cultivars with several cultivars showing potential for processing applications.

Muscadine grape juice was heated in water baths or an autoclave at temperatures of 21, 46, 71, 96 and 121°C for times varying from O-360 min. The ratio of spectrophotometric absorbances at 520 and 420 nm and tristimulus "a" correlated highly with panel scores (r = 0.982 and 0.953, respectively). Anthocyanin content, A520/A420 ratio, and tristimulus "a" value of juices decreased while lightness ("L") and tristimulus "b" value increased with prolonged heating. Juice color became unacceptable as A520/A420 dropped below 3.4 or tristimulus "a" dropped below +22. Color damage from heating progressed in a rbughly logarithmic fashion from 46°C to 121°C with a Q, ,, rate change factor of approximately 1.4. Temperature rather than total heat Input had the greater effect on color changes. Aroma changes preceded unacceptable color changes In the heated juices.