A 50 g sample taken as a horizontal section from the mid-height of an onion bulb was blended with 100 g water for 1 min in a closed plastic mason jar. A 0.5 ml of a headspace sample was drawn and injected into a Perkin Elmer 8500 GC equipped with FPD for detection of sulfur compounds. The major volatiles tentatively identified in onion were thiopropanal S-oxide, methyl propyl disulfide, dipropyl disulfide, and propyl allyl disulfide.
We observed significant variation of peak pattern and height depending on position in a bulb, among bulbs within variety, and between varieties. These results seemed to comply well with taste test. There were no significant correlations between total peak height and bulb weight, soluble solids, or pyruvate concentration in juice extract. Our investigation suggested that this procedure provided better understanding and measurement of onion pungency than pyruvate analysis.
Sensory evaluations (triangle tests) were used to determine if panelists could distinguish, by tasting, cooked wedges of potatoes grown organically, either with or without compost, and conventionally. Mineral and glycoalkaloid analyses of tuber skin and flesh were also conducted. When the skin remained on the potatoes, panelists detected differences between conventional potatoes and organic potatoes, regardless of soil treatment. However, they did not distinguish between organic treatments (±compost) when samples contained skin or between any treatments if wedges were peeled prior to preparation. Glycoalkaloid levels tended to be higher in organic potatoes. In tuber skin and flesh, potassium, magnesium, phosphorus, sulfur, and copper concentrations were also significantly higher in the organic treatments, while iron and manganese concentrations were higher in the skin of conventionally grown potatoes.
Early, mid-, and late-season grapefruit (Citrus paradisi Macf.) were treated with hot air at 46, 48, and 50C for 3, 5, or 7 hours to determine the effects of time and temperature on market quality. Early and late-season fruit were more easily' damaged by the higher temperatures than midseason fruit. Increased times at the lower temperatures had less of a deleterious effect on weight loss, loss of firmness and color, and susceptibility to scalding injury and fungal decay than did shorter times at the higher temperatures. Nevertheless, regression equations predicted that 3 hours at 48C or 2 hours at 49C would not adversely affec: market quality of early and midseason fruit. The suitability of these equations was verified through taste tests of Juice. It may not be possible, however, to raise the treatment temperature for late-season fruit above 47.5C without damaging the quality of juice from these fruit.
Abstract
Tomato fruit were found to accumulate at optimum harvest in proportions of 52-55% all red, 15-20% orange, 7-10% pink, and 15-26% green or overripe. A harvest ratio of 8 parts all red, 3 parts orange, and 1 part pink fruit gave a USDA tomato color index reading ranging from 66.1 to 67.4. In comparison, the all red fruit portion produced a 68.9 to 73.0 color index. Quality changes of the 8:3:1 blend processed juice were found in color, flavor, and ascorbic acid content, but the blends from all cultivars appeared to be commercially acceptable. Taste panel tests indicated no significant preference for all red over blended juice samples. The pH, titratable acidity, and refractive index were not significantly altered by the use of less than red ripe fruit. Utilizing the single harvest ratio of all red, orange, and pink fruits increased per acre yields 20-30%.
`Tiger Baby' mini watermelons were direct seeded into black plastic mulch with drip fertigation irrigation. Drip lines were run for 300 m feet, in excess of that recommended. Single plants were 45 cm apart in 1.5 m rows. Yields were taken from the total 300 m and from the first 90 m of row. Yields only slightly affected by drip tubing type. We also conducted a marketing test with these watermelons. Boxes of 9 melons each (2.5-3.6 kg) were sold at `upscale' grocery chain. Produce managers and customers were surveyed. Size seemed to be the most important selling point, followed by taste. Sales increased once the manager cut a sample melon. In general 40% of the melons sold in the first week and the remaining 60% the second week. Prices averaged $2.00 and minimelons competed favorably with standard sizes.
Numerous species of cacti were introduced in an attempt to diversify the types of fruit trees cultivable under the conditions of the Israeli Negev Desert. The new species were tested in five introduction orchards varying in type of soil, climate and irrigation water. Fruits of the Hylocereus genus, which must be grown on a trellis system under netting, were found to be of an attractive shape, color, appearance and taste. Cereus peruvianus, which grows outdoors, produced beautiful tasty fruits which varied in color from yellow to deep red. Fruits of these species are of the nonclimacteric type and are capable of withstanding long-distance transportation. Some have to be cross-pollinated while others can be self-pollinated. They flower twice or three times a year, bearing fruits from June to November. These types are characterized by a CAM photosynthetic pathway, pointing to high water use efficiency.
Research was initiated at the N.C. State Univ. Horticultural Field Laboratory, Raleigh, to identify cultural practices and tomato cultivars giving superior taste under North Carolina greenhouse conditions. The specialty cultivars `67', `Diana', `Elegance', `Momotaro', and `S630' were grown and harvested, as well as `Trust', which is grown on 85% of the North American greenhouse tomato acreage. Additionally, two fertilizer regimes were provided to the plants: standard greenhouse tomato fertilization (EC ≈1.75 dS·m-1) or high fertilization (EC ≈3.75 dS·m-1). Fertilizers were the same in both treatments. Seeds were started in October 2002 and transplanted, 2 per pot, into `Bato' buckets containing perlite in November. Standard cultural practices were followed, and plants were fertigated using the Harrow Fertigation Manager™ system. Taste tests conducted on three dates revealed differences among cultivars, with `67', `Elegance' and `Momotaro' consistently scoring well. Overall, all test varieties were scored higher than `Trust'; however flavor was somewhat less sweet than anticipated, especially early in the season, averaging 2-3 on a scale of 5, where 5 was “best”. No significant differences were seen between the standard and high fertilization treatments. Differences in total harvest weight were seen among cultivars. `Elegance' and `67' produced fruit consistently well through the harvest season, while the remaining cultivars' yields were sporadic. Harvested fruit were homogenized, and Brix was measured as an indicator of fruit quality. Significant differences in Brix were seen among the cultivars, with `67' significantly higher than all other varieties and `Elegance' and `Momotaro' higher than the remaining cultivars. All specialty cultivars had higher °Brix than `Trust'.
Research shows that food irradiation is a safe food technology effective in reducing pathogenic microorganisms, prolonging shelf-life, and controlling pests, such as fruit flies, to avoid quarantine. However, this technology may not be understood widely by food industry professionals. The purpose of this research was to study the effectiveness of professional development designed with a variety of experiential education strategies targeting food industry regulators, Extension agents, and others in the food industry. The workshop, Improving Safety of Complex Food Items Using Electron Beam Technology, included presentations by experts in food irradiation technology, tours of food irradiation facilities, group activities, and a taste-test of irradiated meats and produce. Data were collected from 19 males and 3 females in the paired workshop pre- and post-tests which assessed participants' knowledge, perceptions, and concerns about food safety and food irradiation, using Likert-type scales. The workshop produced significant knowledge gains. Respondents' perceptions of food safety and food irradiation issues were improved significantly as a result of participation in the workshop. Also, respondents' perceived knowledge and understanding of food safety, food irradiation, and the technology behind food irradiation improved significantly upon completion of the workshop and post-test.
The major limiting factors for commercial marketability of strawberries grown in the Northeast is firmness and shelf-life. The major objective of the research is to study basic and applied aspects of exogenous calcium treatments on yield and quality of New Jersey grown berries. In 1990, 8328-1 and 8237-1 (NJUS advanced selections), and `Earliglow' and `Raritan' standards, were treated with 4 foliar Ca sprays (Nutrical) at 10 day intervals from bloom through harvest. In 1991, sprays (3) were applied at bloom, bloom+15 days, and pre-harvest. An `Earliglow' plot was utilized to test timing: bloom, mid-spray, or pre-harvest. Leaf and fruit samples were taken from treated and untreated plots prior to each application. Instron texture tests were performed to quantify firmness; a taste panel evaluated quality (color, texture, flavor, and overall quality). With multiple sprays, there were no significant differences in yield, fruit size, and Brix%, between treatments; however there were significant differences between genotypes and a genotype-by-treatment interaction. The lone bloom spray treatment reduced fruit size. Ethylene was reduced with calcium treatment, respiration was unaffected. Differences in flavor attributes were genotype specific.
Abstract
A consistent preference by the meadow vole, Microtus pennsylvanicus, for the roots of certain inbred carrot lines and hybrids observed in field plantings suggested the possibility of using these animals to evaluate carrot breeding material for nutritive value and culinary quality. In a preliminary field test, 50 carrot lines representing the full range of feeding damage were planted in a confined feeding experiment. Lines showing no damage and severe damage were selected for controlled feeding trials and further evaluation.
In laboratory ad libitum feeding tests, all carrot diets were inferior to control diets. There was no relationship between vole preference and the nutritive value of the carrots as measured by the growth response of weanling voles. However, vole preference showed a significant positive correlation with the sucrose content of the roots while a significant negative correlation was found between preference and total reducing sugars. Neither growth response nor vole preference was correlated with crude fiber, protein, or total carbohydrates. No correlation was found between taste panel scores for overall rating of carrot samples and ad lib. feeding indexes by the voles.