EFFECT OF SLICING ON THE RATE OF RESPIRATION, ETHYLENE PRODUCTION AND RIPENING OF MANGO FRUIT

The effects of slicing on the rate of respiration and ethylene production and on total soluble solids (TSS) content, texture and microbiological contamination in Julie and Graham mangoes were examined. Effects varied with cultivar, the stage of ripeness and storage temperature. For mature‐green fruit of both cultivars, the respiration rates were highest in cut fruit immediately after slicing, decreasing significantly within the first 12 h of storage at both 5C and 10C and remaining sustained at levels above that of intact fruit throughout the storage period. The effect of slicing on half‐ripe and firm‐ripe fruit was an initial increase in respiration rate followed by a decline to levels equal to that of intact fruit. Slicing had no measurable effect on ethylene production. TSS content was greatest in sliced tissue at the higher temperatures while there was no effect of slicing on tissue firmness. Generally, storage at lower temperatures reduced the negative effects of wounding, including the level of microbial contamination.     

PRODUCT DEVELOPMENT AND NUTRACEUTICAL ANALYSIS TO ENHANCE THE VALUE OF DRIED FRUIT

ABSTRACT

Value‐added fruit products suitable for production by small‐scale farmers and processors were developed and evaluated. Apples, blueberries, peaches and strawberries from local growers were processed into a dried fruit product. The total phenolics, total anthocyanins and oxygen radical absorbing capacity (ORAC) were determined. Drying the fruit concentrated total phenolics, total anthocyanins and ORAC levels as compared to fresh fruit. The nutraceutical components of the blueberries, peaches and strawberries of the local dried fruit were higher than those of commercial dried fruit purchased at a natural food store. The dried fruit from both the local and commercial fruits was used to create a fruit pie filling for consumer evaluation. Consumer acceptance of fruit pie filling from dried fruit grown locally and dried commercial fruits was evaluated using a 9‐point verbal hedonic scale and a 5‐point Just About Right scale. In terms of consumer evaluation, the pie fillings made from local dried fruits were either better or at parity with those from commercial products. In addition to the nutraceutical benefits, the pie fillings were consumer acceptable products that could represent an avenue for small‐scale farmers to add value to surplus fruit.

PRACTICAL APPLICATIONS

Complete utilization of fruit crops is a key component to the success of small farm operations. Excess fruit crops can be dried (or processed in other manners) and used to create many value‐added products. Increased consumer awareness of healthy food products provides a niche market for these fruit products. In this research, the nutraceutical benefits of fresh and dried apples, blueberries, peaches and strawberries were investigated and the consumer overall acceptance of a pie filling produced from these dried fruit was shown.

     

Effect of freezing grape berries and heating must samples on extraction of components and composition parameters of red wine grape varieties

Juices from grape samples subjected to two storage methods (fresh and frozen) and two post-homogenisation treatments (21^oC and 71^oC) were examined for extraction of grape berry components and compared to a microvinified wine made from the same lot of fresh grapes. Cabernet Franc ( Vitis vinifera ) and Cynthiana ( Vitis aestivalis ) grapes were evaluated in 2003. Cabernet Franc, Cabernet Sauvignon ( Vitis vinifera ), Chambourcin (interspecific hybrid) and Cynthiana grapes were evaluated in 2004. Fresh grapes from each variety were sampled, analysed and prepared for microvinification. Frozen grapes of all varieties were thawed and analysed at the same time. For all varieties in both years, heating the must of fresh or frozen grapes increased the titratable acidity (11–58%), tartaric acid levels (12–110%), potassium content (15–62%), darkness (31–97%), red colour (54–1517%) and total red pigment values (36–1171%) of juice as compared to the juice from unheated must. For all varieties in 2004, heating the must from fresh or frozen grapes increased total phenolics (43–619%) of juice as compared to the juice from unheated must. Compared to fresh grape processing, freezing the grapes and then processing at 21^oC or 71^oC had varying results (increases and decreases) regarding the extraction of components in all varieties and both years but usually provided juice with composition most similar to that of the red wine produced by microvinification. Although the degree of extraction of individual components in the juice is influenced by selection of grape storage and must processing procedures, consistency of handling and procedure provided consistent results with low variability.     

Yeast Inhibition in Grape. Juice Containing Sulfur Dioxide, Sorbic Acid, and Dimethyldicarbonate

Sulfur dioxide (SO₂), sorbic acid (SB), dimethyldicarbonate (DMDC), and their combinations were studied for suppression of fermentation at 21°C or 31°C in grape juice inoculated with 2, 200, or 20,000 colony forming units (CFU)/mL of yeast. The other preservatives did not suppress as well as DMDC. The DMDC (0.8 mM) prevented fermentation at all inoculation levels at both temperatures, except that inoculated with 20,000 CFU/mL at 21°C. The 0.8-mM level of SO₂+DMDC. and SB + DMDC orevented fermentation in samoles inoculated with 2 or 200 CFU/mL at 31°C. Storage at 31°C decreased effectiveness of SO₂, SB, and SO₂+ SB but increased effectiveness of DMDC, SO₂+ DMDC, and SB+DMDC (0.8 mM level).     

ETHNIC DIVERSITY AND ITS IMPACT ON COMMUNITY SOCIAL COHESION AND NEIGHBORLY EXCHANGE

Putnam's “constrict theory” suggests that ethnic diversity creates challenges for developing and sustaining social capital in urban settings. He argues that diversity decreases social cohesion and reduces social interactions among community residents. While Putnam's thesis is the subject of much debate in North America, the United Kingdom, and Europe, there is a limited focus on how ethnic diversity impacts upon social cohesion and neighborly exchange behaviors in Australia. Employing multilevel modeling and utilizing administrative and survey data from 4,000 residents living in 148 Brisbane suburbs, we assess whether ethnic diversity lowers social cohesion and increases “hunkering.” Our findings indicate that social cohesion and neighborly exchange are attenuated in ethnically diverse suburbs. However, diversity is less consequential for neighborly exchange among immigrants when compared to the general population. Our results provide at least partial support for Putnam's thesis.     

Chemical Composition and Nutritional Quality of Faba Bean (Vicia faba L. Minor) Based Tofu

Chemical composition and antinutritional factors in soy and faba beans and tofus produced thereof were evaluated. Both bean curds had higher protein contents (55.7 and 82.0% dry basis for soy and faba bean curds, respectively) than the corresponding raw beans. Tofu made from faba bean (FBT) contained only 1.5% total lipids (dry basis) compared to 34.4% in soybean tofu (SBT). Antinutritional and flatulence factors were much lower in FBT. Favism factors were not examined. In vitro studies showed that SBT and FBT are comparable in terms of digestibility and amino acid availability.     

The Sheer Opacity of Contemporary Enclosure

Skins & Screens , the graduate-level elective studio offered at the University of Pennsylvania, posits the building surface as a dynamic condition, simultaneously real and illusory, opaque and evanescent. Termed sheer opacity , this quality of enclosure provides an investigative focus for the consideration of surface as a dynamic perceptual field, a site for the mediation of physical and perceptual phenomena. Close analysis of selected work of the West Coast art movement Light and Space and that of contemporary installation artists inspired projects that used sheer opacity to examine the possibility of transforming space through the design of the building surface. Projects were developed through a series of "layers" in which students made installations, material constructs, digital simulations, and large-scale detail studies of their proposals.