Nutrition & Food Science
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Item Feasibility of Soluble Leaf Proteins as a Carrier for Vitamin D(2009) Cherian, Ansu Elizabeth; Lo, Y. Martin; Food Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Resurgence of vitamin D deficiencies in recent years has ascribed the need for expansion of fortification strategies in food. Alluding to the fat soluble and sensitive chemical nature of vitamin D, existing fortification strategies invariably require using a substantial amount of fat as carriers for vitamin D. Though milk proteins have demonstrated good binding properties with vitamin D; allergen issues, lactose intolerance, and the need to cater to vegan population deter its extensive use. In this study, soluble leaf proteins extracted from low-alkaloid tobacco leaves were investigated as a possible carrier. Crude tobacco leaf proteins were extracted by a high-throughput mechanistic process, followed by a freeze-drying process to encapsulate vitamin D. Up to 84.68% (w/w) of vitamin D was successfully retained by tobacco leaf proteins using the process developed, indicating that crude leaf protein recovered from tobacco could be employed as an effective carrier for vitamin D.Item CHARACTERIZATION OF ALGAL BIOMEAL FOR APPLICATIONS IN FOOD(2009) Sanghvi, Avani Mukesh; Lo, Martin; Food Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Conventionally used as animal feeds, microalgae are now cultivated for products such as omega-3 fatty acids, resulting in a high amount of biomass as by-product. The biomass obtained after the extraction of DHA from Crypthecodinium cohnii is called `algal biomeal'. Being nutritionally rich, the biomeal has potential to be used as a value-added ingredient in human food and animal feeds. Evaluation of the biomeal properties resulted in the development of a water-based sauce formulation which was analyzed for its proximate composition, textural attributes and microbial stability. The sauce was rich in carbohydrate and protein with low fat and ash content. It was microbiologically and texturally stable under refrigeration. This research shows that development of a shelf-stable palatability enhancer using algal biomeal offers a new ingredient for the food and feed industries, whereas the ability to produce a value-added ingredient also offers a viable option for algal biomeal.Item Antioxidant and Anti-proliferative properties of selected grape seed extracts(2009) Bloom, Raquel Zorah; Yu, Liangli; Nutrition; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)This study examined chardonnay, muscadine, concord, and ruby red grape seed oil and flour extracts for antioxidant and anti-proliferative properties. The extracts were tested for total phenolic content, DPPH* · and ABTS*+ ·radical scavenging capacity and effect against HT-29 cancer cell proliferation. All of the grape seed extracts exhibited ABTS*+ · and DPPH*· radical quenching activity. The flour extracts from chardonnay demonstrated the highest ABTS*+· radical quenching capacity of 186 μμmoles trolox equivalents/g and DPPH* · radical quenching activity of 30 μμmoles trolox equivalents/g. All of the grape seed oil and flour extracts contained significant levels of phenolics. Chardonnay grape seed flour extract displayed the most prominent dose dependent anti-proliferative effect. Muscadine and ruby red, but not concord grape seed flour extracts, also exhibited anti-proliferative activities. The collected data advocate for the potential of grape seed extracts as dietary sources of anti-proliferative and antioxidant components.Item Nutraceutical Properties of Low alpha-Linolenic Soybeans Grown in Maryland(2009) Whent, Monica; Yu, Liangli; Food Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Eight soybean genotypes grown in Maryland were analyzed for total phenolic content (TPC), antioxidant capacity, isoflavone composition, lutein content, tocopherol composition, and fatty acid profile. The soybean samples consisted of seven low alpha-linolenic (18:3n-3) experimental lines and one standard cultivar for comparison. 18:3n-3 levels were negatively correlated with oleic acid (18:1n-9). The isoflavones daidzein and genistein were positively correlated with 18:3n-3 levels. Alpha-tocopherol, gamma-tocopherol, and total tocopherols were negatively correlated with 18:3n-3. Two of the reduced 18:3n-3 lines contained significantly higher lutein levels than the ordinary cultivar. All low alpha-linolenic lines contained similar antioxidant capacity to the non-modified genotype. The results of this study show that the Maryland-grown low 18:3n-3 soybeans are sources of antioxidants and isoflavones and may be consumed for health benefits. Specific genotypes may be selected for food production to obtain the most desirable combination of nutritional, nutraceutical, and chemical properties.Item Assessment of Foodborne Pathogen Survival During Production and Pre-harvest Application of Compost and Compost Tea(2009) Ingram, David Thomas; Joseph, Sam W; Meng, Jianghong; Food Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The use of compost in crop production systems as a soil amendment is recognized by both conventional and organic plant production practitioners as a means to increase yields and reduce the incidence of foliar diseases. Compost tea (CT), an aqueous extract of the biological components of compost, is also recognized as a means to broadcast the phytopathogen-reducing components of compost directly to the surfaces of plants where many foliar diseases become established. CT has been shown to control the proliferation of a variety of foliar diseases in many turf, crop and horticulture production systems when applied directly to the foliar surfaces of plants. This dissertation research was designed to address several pre-harvest food safety issues concerning compost and compost teas. Three objectives were pursued to establish whether the use of compost and compost teas as pre-harvest practices may introduce foodborne pathogens into the food supply and, therefore, contribute to the incidence of foodborne illness. The first objective involved a microbiological survey of commercially available compost in the U.S. to determine the prevalence of fecal coliforms, Escherichia coli, Salmonella and enterococci that might be reaching consumers through contaminated fruit and vegetables. The second objective was to investigate the ability of these foodborne pathogens to propagate during the production of CT. The third objective involved a field study examining the potential of CT to disseminate E. coli into organic and conventional strawberry production systems. The effects of CT on the fruit yield, phytopathogen suppression, as well as the potential for foodborne pathogen survival on the fruit surfaces were examined. This project provided important information and recommendations for the safe production and pre-harvest application of compost and compost teas. It was contended that, with proper attention to the manufacture and storage of compost and with simple modification of current trends in CT production systems, the current threshold of pre-harvest introduction of foodborne pathogens could be significantly reduced.Item Acid Modification of Psyllium(2008) Pei, Xiaoyin; Yu, Liangli; Food Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Psyllium, a type of dietary fiber, has been shown to have various health benefits including cholesterol lowering, hypoglycemic, cancer prevention, and laxative effects. However, due to its extremely strong water-holding and gel-forming capacities, incorporation of psyllium into food products on the required amount per serving for health claim is difficult. This study evaluated the effect of acid treatment on water up-taking, swelling, gelling and bile acid binding capacities of psyllium samples. The acid treatments were conducted at different reaction temperatures (25, 37.5, and 50 °C) with different psyllium - solvent ratios (1:2.5, 1:5, 1:7.5, and 1:10 g/mL). The result showed that reaction temperature influenced the effectiveness of acid treatment on physical/chemical properties of psyllium samples significantly, while effects of different psyllium - solvent ratios were not significant. This implicated the acid modification at a high temperature might be a possible method to improve the physical/chemical properties of psyllium for incorporation in food.Item Promoting the production and consumption of wheat-based functional foods rich in antioxidants.(2008-11-20) Luther, Marla West; Yu, Liangli; Food Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The present study evaluated the effects of solid state yeast treatment and thermal processing on the extractability and in-vitro bioavailability of antioxidants from wheat bran and whole-wheat pizza crusts, and developed sample outreach materials for promoting the consumption of whole-wheat functional foods. The first section analyzed the effect of solid-state yeast treatment on the extractable antioxidant properties of wheat bran. Wheat bran was treated with ten commercially available food grade yeasts under solid state conditions. Antioxidant properties were evaluated by measuring total phenolic content, and radical scavenging capacities against the cation ABTS, peroxyl (ORAC), DPPH (RDCS), and hydroxyl (HOSC) radicals. Results showed that under the selected conditions, yeast strain LBE.11 was able to increase ORAC and HOSC radical scavenging by 50% and 67%, respectively. The second part of this study evaluated the impact of bran particle size, fermentation time, and baking time and temperature on the 100% ethanol extractable antioxidant capacities of whole wheat pizza crust. Results showed that pizza crusts produced with reduced bran particle size maintained antioxidant capacity throughout thermal processing. At 18 hrs of fermentation RDSC and TPC values of the pizza crusts were increased by 17% and 23%, respectively. Increasing baking temperature increased RDSC values by 14 and 17% for pizza crusts prepared with Lakin and Trego variety wheat, respectively. The third part of this study analyzed the in-vitro bioavailability of wheat antioxidants in baked pizza crusts. Antioxidant properties were evaluated by measuring total phenolic content, and radical scavenging capacities against the cation ABTS, peroxyl (ORAC), DPPH (RDCS), and hydroxyl (HOSC) radicals. Pizza crusts with higher available antioxidants may have a greater level of bio-available antioxidants. The final segment of this research was to develop a tri-fold for promoting the consumption of whole wheat foods. The tri-fold was designed to include food-specific knowledge, consumption consequences knowledge in addition to recipes and directions, and nutritional facts. Integrating research findings into outreach materials may be an effective way to increase functional food consumption. Results from these studies indicate that there are numerous ways to increase antioxidant levels in the diet.Item Feasibility of Extracting Solanesol from Tobacco Biomass as a Byproduct Following Protein Recovery(2008-08-08) Machado, Peter; Lo, Y. Martin; Food Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)The solanesol content in tobacco biomass, a waste derived from tobacco leaves obtained from the low alkaloid cultivar 'MD 609LA' that had been processed for protein recovery, was evaluated at different points during processing. Solanesol, a precursor to coenzyme Q10 and Vitamin K2, is a high value compound found in significant amounts in tobacco leaves and could potentially increase the profitability of tobacco when grown at high density and harvested mechanically for nonsmoking applications. Respective solanesol yields of various extraction methods were assessed using an optimized reverse-phase high performance liquid chromatography (RP-HPLC) method. Solanesol was detected in the waste streams generated during tobacco protein processing, at 0.047% and 0.331% dry weight of the biomass waste and chloroplast sediment, respectively. Microwave-assisted extraction was found the most efficient extraction method in terms of solanesol yield, extraction time, and solvent usage. This research shows that the extraction of solanesol after protein recovery is a feasible operation and could increase the overall profitability of biorefining tobacco for alternative, value-added uses.Item Whole surface image reconstruction for machine vision inspection of fruit(2008-05-15) Reese, Daniel; Lo, Y Martin; Food Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Automated imaging systems offer the potential to inspect the quality and safety of fruits and vegetables consumed by the public. Current automated inspection systems allow fruits such as apples to be sorted for quality attributes such as weight, color, and size based on imaging a portion of the surface of each fruit. However, to ensure the inspected fruits are free of defects and contamination, the whole surface of each fruit must be imaged. The goal of this project was to develop an economical module capable of providing whole surface imaging of apples using mirrors and a single camera. Different configurations of flat and concave mirrors were examined and their ability to approach 100% of an apple's surface were characterized and compared. Specific configurations of two, four, or six parabolic concave mirrors were found capable of imaging an entire apple surface at desired image size for inspection without image distortion. This imaging module developed could be integrated into existing automated inspection systems to leverage the effectiveness of food safety inspection.Item Distribution and Evolution of the Palatinose (pal) operon in Enterobacter sakazakii(2008-05-05) Lamm, Katelyn Amber; Meng, Jianghong; Food Science; Digital Repository at the University of Maryland; University of Maryland (College Park, Md.)Enterobacter sakazakii, an opportunistic enteric pathogen found in infant milk formula, is associated with outbreaks of meningitis and septicemia among immunocompromised newborns. A biochemical signature of E. sakazakii metabolism is its ability to degrade palatinose. The prevalence of the pal operon among E. sakazakii remains unknown. Studying 144 E. sakazakii strains, the prevalence of five pal genes (palZ, K, Q, E, and G) were assessed. Only 22% of strains retained all five genes in the pal operon, while another 22% of strains retained four of the five genes. Genetic instability of the pal operon was seen in phylogenetic studies which revealed evidence for horizontal gene transfer of the pal genes among strains and revealed variation in the structure and distribution of the pal operon. The genetic instability of the pal genes inferred from this study rejects using this operon as a diagnostic target for E. sakazakii detection in infant formula.