The vermicomposting of coffee grounds shows great promise for urban areas and university campuses. Several studies have examined using coffee grounds as a substrate for vermicomposting, however, little is known about its effect on plant growth, yield and quality. Therefore, two studies were conducted to assess these effects on greenhouse spinach and field grown bell peppers. Coffee vermicompost (VC) was utilized in a greenhouse spinach study over two spring growing seasons (2011 and 2012). Coffee VC was added to a 1:1:1 (peat, soil, sand) medium by volume (0, 25, 50 and 75%) in 4.5 L clay pots and seeded with `Bloomsdale Longstanding' spinach (Spinacia oleracea). Growth parameters evaluated were fresh leaf weight (FLW), leaf area (LA), spinach plant height, number of leaves, fresh leaf ascorbic acid (AA) and dry leaf nitrate (DLN). In 2011, the highest FLW, LA, number of leaves, AA and nitrate content were seen at the 75% VC application rate. Many parameters were correlated: The FLW and the VC application rate (r=0.41, P<0.0001); the AA content in leaves and the VC application rate (r=0.60, P<0.0001); and the AA and nitrate content in leaves (r=0.45, P=0.011). In 2012, the greatest FLW, height and number of leaves were observed at the 50% VC application rate; the highest nitrate content at 75% VC application rate, with no difference in AA content. A field study was conducted over three seasons (2009–-2011) to compare four treatments (coffee VC, dairy compost, standard fertility (SFT) and no treatment) for their effects on growth, yield, and AA content of bell peppers. Coffee VC and dairy compost were applied to beds at the rate of 22 t/ha and SFT was applied as 212 kg/ha 12:12:12 (N:P:K). Parameters evaluated were total number and weight of marketable and cull (unmarketable) pepper fruits, plant height, leaf chlorophyll index, and fresh fruit AA content. There were no differences detected for pepper fruit yields or AA content, however, plant height and chlorophyll index were greater for the VC and SFT treatments than for the compost and control treatments. These results indicated that coffee VC can improve the yield of greenhouse spinach and that the AA content does not decrease with higher VC application rates, even as nitrate content increases. Results of the bell pepper field study indicated that the coffee VC treatment produces similar growth, yield and AA content as SFT.

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Three hydrocolloid-lipid emulsion coatings were developed using Humkote brand partially hydrogenated cottonseed and vegetable oil, and one of three combined hydrocolloid bases: xanthan gum and propylene glycol alginate (xanthan coating), locust bean gum and xanthan gum (locust bean gum coating), and maltodextrin. Sensory testing using a ranking preference test indicated that these coatings had acceptable appearance and palatability. Quality characteristics of green bell peppers (Capsicum annum L. cv. King Arthur) measured during the 5-week storage period included: respiration rates, chlorophyll content, surface color, puncture force, pectin (uronic acid) content, ascorbic acid (AA) and dehydroascorbic acid (DHA) content, and cumulative weight loss. No significant differences between coated and uncoated peppers were noted in tests for respiration, puncture force, hue angle, chlorophyll content, and AA content. Uncoated peppers had significantly inferior moisture retention (p<0.05), which caused them to be unsaleable after 8 days, while coated groups were saleable for an additional 6 to 8 days. Uncoated fruits also had greater uronic acid breakdown (p<0.05) and higher DHA content (p<0.06) than coated peppers. Significant weekly changes (all treatment groups combined) included linear increases in respiration rates (p<0.01) and moisture loss (p<0.01), increasing linear and quadratic trends in uronic acid content (p<0.01 for both trends), increasing quadratic trends for both chlorophyll and AA content (p<0.05, p<0.01, respectively), and decreasing linear and quadratic (p<0.05 for both trends) in DHA content. The only significant difference between coated groups was in chroma value, with maltodextrin coated peppers appearing less vivid than locust bean coated peppers. Overall, all three coatings performed equally well during the storage study. However, coatings with higher lipid content, which included xanthan gum and locust bean gum groups, withstood humidity changes better than the maltodextrin coated peppers. Coating application provided the greatest benefits in terms of texture maintenance through water retention and prevention of pectin breakdown, despite the lack of differences observed in puncture force. Coatings may also have prevented AA oxidation as demonstrated by the higher DHA content in uncoated groups, however AA patterns do not confirm this concept. Future research should be directed toward further minimizing textural changes and maximizing coating durability. / Ph. D.

Two lipid-based edible coatings, Apex B (AC Humko, Memphis, TN) and Durafresh (Pacrite, Ecoscience Produce Systems, Orlando, Fl) were evaluated for their ability to preserve post harvest quality changes in green bell peppers (Capsicum annum L. cv. King Arthur). Post harvest storage quality conditions tested included respiration rates, weight, color and texture changes, and stability of ascorbic acid (AA) and dehydroascorbic acid (DHA) content. Results indicated that no appreciable changes between days or treatment groups occurred in three of the parameters tested: weight, texture, and hue angle (p>0.05 for all parameters). Significant weekly changes were seen in respiration rates, dehydroascorbic acid content, and chromaticity values. Respiration rates and DHA were significantly higher during the last two weeks of the study (p=0.0001, p=0.0001 respectively). Chromaticity values were significantly lower, indicating a more faded color on the 14th day of the study alone (p=0.0097). Initial AA levels were much lower than expected (average initial content=78.72mg/100g). Significant differences between coated and uncoated pepper groups were seen in AA and DHA levels. AA content was found to be significantly lower in coated peppers (p=0.0279), while DHA levels were significantly higher in coated groups (p=0.0126). Overall, coated groups differed little from uncoated counterparts, except in the area of vitamin content in which the coated peppers showed an increase in vitamin breakdown. Despite the results, modifications of lipid coatings are needed, such as creating bilayer and composite coatings that contain either polysaccharide or protein constituents to enhance coating effectiveness. / Master of Science