Agriculture Commons^™

Quality And Safety Attributes Of Sun-Dried Raisins From Afghanistan, Stacy A. Mccoy

Open Access Theses

Raisins are an important export commodity for Afghanistan, however, Afghan packers are challenged to export to markets seeking high quality products due to limited knowledge regarding their quality and safety. To evaluate this, Afghan raisin samples from pre-, semi-, and post-processed raisins were obtained from a raisin packer in Kabul, Afghanistan. The raisins were analyzed and compared to U.S. standards for processed raisins. The samples tested did not meet U.S. import standards for embedded sand, but the process used to clean the raisins is suitable to maintain food safety standards.

Previous Afghan raisin shipments have been rejected from the U.S. …

African Starchy Foods, Gastric Emptying, And Starch Digestion In Malian Stunted Children, Fatimata Cisse

Open Access Dissertations

Starch serves as the main energy source in cereal and tuber-rich diets, and its glycemic response profile has been associated with health-related conditions. Sorghum and millet are known to have relatively low starch digestibility, a potentially desirable property for controlling blood glucose response and providing sustained energy. Gastric emptying rates of traditional sorghum and millet-based African foods of the Sahelian region (couscous, thick and thin porridges made from millet and/or sorghum) were compared to those of non-traditional "modern" foods that are mostly consumed in urban areas using a non-invasive 13C-labelled octanoic acid breath test in healthy volunteers. The obtained results …

Differences In Carbon Dioxide Evolution From Samples Of Shelled Corn Subjected To Various Storage Treatments, Cininta Alp Pertiwi

Open Access Theses

Shelled corn was collected from two sources - commercial grain elevators and corn harvested from Purdue University farms and then frozen until tested. Using a carbon dioxide (CO₂) test kit manufactured by Woods End Laboratories, CO₂ evolution measurements were conducted on shelled corn from both sources, after the samples were re-wetted to approximately 21% moisture content, placed in a 473 ml glass jar, and incubated at room temperature for 72 hours. The CO₂ test kit uses a gel that changes color in response to a change in the level of CO₂ in the surrounding air. …

Characterization Of Water-Solid Interactions In Crystalline Ingredients And Development Of Deliquescence Measurement Recommendations, Matthew C. Allan

Open Access Theses

There are five major mechanisms of water-solid interactions. The primary focus of this thesis was on two of these: deliquescence and hydrate formation. Many crystalline food ingredients are deliquescent compounds (e.g., NaCl, sucrose, and ascorbic acid) and some are both deliquescent and hydrate formers (e.g., glucose, thiamine HCl, citric acid). Deliquescence is the first order phase transformation of a crystalline solid to a solution above a critical relative humidity (RH) known as the deliquescence point (RH0). A crystalline hydrate is a pseudo-polymorph in which water is incorporated into the crystal structure, altering the molecular formula and the physical properties.^ To …

Evolution Of Food Quality Demand In The Food Service Industry In China: The Case Of Duck, Rachel Alison Carnegie

Open Access Theses

Booming economic growth and rising consumer incomes have impacted food preferences and purchasing behavior in China. At the same time, several internationally publicized food safety incidents, particularly in the animal husbandry sector, have heightened awareness of and concern for food safety and quality in meat and dairy. Rising quality demand and safety concerns have been studied at length in the food retail sector, but also appear to be important in the food service industry. This research uses data from a survey of duck restaurant managers and consumers in Beijing, Shanghai, Chengdu, and Guangzhou to determine preferences and willingness to pay …

Physical And Chemical Attributes Of A Genetically Modified Fruit Pectin, Carl Patrick Littrell

Open Access Theses

Pectin is an important polymer used in the food industry as a thickening and gelling agent. Though pectin is ubiquitous in plants, chemical and structural differences among pectin molecules prevent most from being viable for industrial use. Enzymes found naturally in fruit cell walls during the ripening process impair many desirable attributes of fruit pectins, rendering them unsuitable for industrial applications. Pectin methylesterase (PME) is one such enzyme whose expression can be altered during ripening through the use of recombinant genetic engineering. Reduction in levels of PME results in increased degree of methylation and molecular size of pectin, greatly increasing …

Fact Or Fiction: Random Mating In Field Populations Of Western Corn Rootworm (Diabrotica Virgifera Virgifera Leconte) Emerging On Bt And Refuge Corn Plants, Steven Joel Smith

Open Access Theses

The western corn rootworm, or WCR, (Diabrotica virgifera virgifera LeConte) is the most significant pest of field corn (Zea mays) in the United States, and has recently expanded its range into Europe. Since 2004, hybrid corn containing Bt toxins targeting the corn rootworm complex have been heavily adopted and are now the primary control measure for this pest in North American corn production. ^ The evolution of resistance is an ongoing concern, and to ensure Bt products will retain their usefulness, insect resistance management (IRM) tactics using various refuge structures have been adopted. One of the key …

Crystallization Inhibitor Properties Of Polymers And Effects On The Chemical And Physical Stability Of L-Ascorbic Acid During Preparation And Storage, Belinda Christina

Open Access Theses

Crystalline L-ascorbic acid (VitC) is an essential nutrient solid that is widely used in food applications for fortification, antioxidant, and label claim purposes. VitC is known as one of the most unstable vitamins, and its content must be declared on food labels. Interest has been increasing in creating amorphous solid structures for improving the solubility and/or dissolution rates of crystalline compounds. One of the most promising methods studied to prevent the crystallization of an amorphous solid is the use of polymers in dispersions, although the specific polymer properties that lead to the best physical stability for a particular type of …

Shrinkage Prediction During Pasta Dehydration, Gina Michelle Bressani

Open Access Theses

Shrinkage models from different fields of study were reviewed. Pasta was used as a model to further develop the hypothesis of predicting shrinkage in terms of the rate of relaxation and the rate of moisture loss. An extended literature review of pasta properties, such as isotherms, diffusivity, glass transition, rheological properties, and shrinkage was conducted. Isotherm and glass transition models were developed from the literature data acquired. Creep was tested with a 25 mm-diameter flat plate at 20 to 40°C at varying moisture content. Viscoelastic properties for the Burgers model for creep were determined, where higher moisture content samples resulted …

Characteristics And Practices That May Lead To Listeria Monocytogenes Contamination In Retail Delis, Jingjin Wang

Open Access Theses

The foodborne pathogen, Listeria monocytogenes, can contaminate ready-to-eat (RTE) deli meats at retail delis, since retail delis provide an ideal environment for L. monocytogenes growth. Current risk assessment indicates that 83% of listeriosis cases from RTE deli meats are all from RTE deli that are sliced at retail delis. Strategies for controlling L. monocytogenes in retail establishments are essential to prevent post-processing contamination of RTE foods. In order to determine the potential risk factors associated with L. monocytogenes contamination and develop best practices to reduce L. monocytogenes , we sampled the retail establishment environment, isolated L. monocytogenes, and …

Wheat Stored In Triple Layer Plastic Bags: Protection Against The Rice Weevil, Sitophilus Oryzae L. (Coleoptera: Curculionidae) And The Effect Of Air Leaks On Hermetic Storage, Daniel Thomas Martin

Open Access Theses

Triple layer bags consisting of two inner layers of 80 micron thick high-density polyethylene (HDPE) surrounded by an outer woven polypropylene bag have proven to be an effective technology for hermetic storage of cowpea and to prevent loss caused by the cowpea bruchid, Callosobruchus maculatus Fabricius (Coleoptera: Chrysomelidae). This bagging technology is called the Purdue Improved Crop Storage (PICS) system. If PICS bags prove useful for protecting other crops against their insect pests during storage it would allow farmers to store these commodities for longer periods of time to increase personal food availability and market flexibility. Accordingly, PICS bags were …