Stephen R. Drake

Bio: Stephen R. Drake is an academic researcher from Agricultural Research Service. The author has contributed to research in topics: Codling moth & Fruit tree. The author has an hindex of 23, co-authored 86 publications receiving 2011 citations. Previous affiliations of Stephen R. Drake include United States Department of Agriculture.

Dielectric properties of apple cultivars and codling moth larvae

Abstract: Dielectric properties of four apple cultivars and third and fifth instars codling moth (Cydia pomonella) were measured between 30 MHz and 3000 MHz at 5°C to 55°C, using the open-ended coaxial-line probe technique. Dielectric constant of apples decreased with frequency and decreased slightly with increasing temperature. The dielectric loss factor increased linearly with temperature in the radio frequency range but was nearly constant at the microwave frequencies. Minimum dielectric loss factor of apples was observed at about 915 MHz. Dielectric constant and loss factor were not influenced by cultivar, pulp section or degree of ripeness of apples. Firmness and titratable acidity in apples decreased, while soluble solids content increased significantly due to ripeness. But these properties were not correlated with the dielectric properties. Dielectric constant and loss factor of codling moth larvae followed a similar pattern of variation with frequency and temperature as for the apples. The dielectric properties of third instars codling moth were higher than those of the fifth instars in the radio frequency region. Dielectric constant and loss factor of the insect were much higher than that of the apples at frequencies lower than 2450 MHz, suggesting that differential heating may be untenable at 2450 MHz or higher frequency for codling moth larvae in the apple host.

Postharvest Use of Sucrose Polyesters for Extending the Shelf-life of Stored ‘Golden Delicious’ Apples

Abstract: The post-storage uses of a sucrose-fatty acid polyester (SPE) formulation, commercial fruit wax and a combination of both were investigated on ‘Golden Delicious’ apples after fruit were removed from both controlled atmosphere (CA) and refrigerated storage. Quality parameters measured included color (skin and internal), firmness, soluble solids and titratable acidity. Physiological parameters measured were carbon dioxide and ethylene concentrations both evolved and internal. Refrigerated stored apples, treated with SPE, displayed retarded color development, higher acid and greater firmness values compared to controls. CA stored, treated apples possessed similar attributes but no firmness retention. Ethylene evolution was reduced in SPE-coated apples. In comparison to control apples, an internal accumulation of carbon dioxide and a reduction in ethylene was observed.

Potential perspectives of bio-nanocomposites for food packaging applications

Abstract: Research and development of bio-nanocomposite materials for food applications such as packaging and other food contact surfaces is expected to grow in the next decade with the advent of new polymeric materials and composites with inorganic nano-particles. This article reviews different types of new bio-based materials, such as edible and biodegradable nanocomposite films, their commercial applications as packaging materials, regulations and future trends. Special emphasis is given to the advantages of nanotechnology application in order to improve the mechanical and oxidation stability, the barrier properties, and eventually the biodegradability of conventional polymeric matrices.

Trends in microwave- related drying of fruits and vegetables

Abstract: Microwave (MW)-related (MW-assisted or MW-enhanced) combination drying is a rapid dehydration technique that can be applied to specific foods, particularly to fruits and vegetables. Increasing concerns over product quality and production costs have motivated the researchers to investigate and the industry to adopt combination drying technologies. The advantages of MW-related combination drying include the following: shorter drying time, improved product quality, and flexibility in producing a wide variety of dried products. But current applications are limited to small categories of fruits and vegetables due to high start-up costs and relatively complicated technology as compared to conventional convection drying. MW-related combination drying takes advantages of conventional drying methods and microwave heating, leading to better processes than MW drying alone. This paper presents a comprehensive review of recent progresses in MW-related combined drying research and recommendations for future research to bridge the gap between laboratory research and industrial applications.

Advances in Edible Coatings for Fresh Fruits and Vegetables: A Review

Abstract: Edible coatings are an environmentally friendly technology that is applied on many products to control moisture transfer, gas exchange or oxidation processes. Edible coatings can provide an additional protective coating to produce and can also give the same effect as modified atmosphere storage in modifying internal gas composition. One major advantage of using edible films and coatings is that several active ingredients can be incorporated into the polymer matrix and consumed with the food, thus enhancing safety or even nutritional and sensory attributes. But, in some cases, edible coatings were not successful. The success of edible coatings for fresh products totally depends on the control of internal gas composition. Quality criteria for fruits and vegetables coated with edible films must be determined carefully and the quality parameters must be monitored throughout the storage period. Color change, firmness loss, ethanol fermentation, decay ratio and weight loss of edible film coated fruits need to b...

Innovations in the Development and Application of Edible Coatings for Fresh and Minimally Processed Fruits and Vegetables

Abstract: One of the major growth segments in the food retail industry is fresh and minimally processed fruits and vegetables. This new market trend has thus increased the demands to the food industry for seeking new strategies to increase storability and shelf life and to enhance microbial safety of fresh produce. The technology of edible coatings has been considered as one of the potential approaches for meeting this demand. Edible coatings from renewable sources, including lipids, polysaccharides, and proteins, can function as barriers to water vapor, gases, and other solutes and also as carriers of many functional ingredients, such as antimicrobial and antioxidant agents, thus enhancing quality and extending shelf life of fresh and minimally processed fruits and vegetables. This review discusses the rationale of using edible coatings on fresh and minimally processed produce, the challenges in developing effective coatings that meet the specific criteria of fruits and vegetables, the recent advances in the development of coating technology, the analytical techniques for measuring some important coating functionalities, and future research needs for supporting a broad range of commercial applications.

Methods to Reduce/Eliminate Pathogens from Fresh and Fresh-Cut Produce

Abstract: Scope In response to the current public health concerns with the microbiological safety of fresh and fresh-cut produce, researchers have investigated the efficiency of numerous physical, chemical, and biological methods for reducing the microbiological load of produce. This chapter focuses on this growing area of research with a particular emphasis on human pathogenic microorganisms; however, research related to mitigation treatment effects on nonpathogenic organisms is also included. There have been several reviews that address this topic and they are pointed out throughout the chapter; therefore, the focus here is on the latest and most significant research findings. A matrix (Table V-1) summarizing the characteristics of intervention methods is also included at the end of the chapter.