Lloyd T. Walker

Bio: Lloyd T. Walker is an academic researcher from Texas A&M University. The author has contributed to research in topics: Azoxymethane & Aberrant crypt foci. The author has an hindex of 17, co-authored 77 publications receiving 1199 citations. Previous affiliations of Lloyd T. Walker include University of Alabama in Huntsville & Alabama Agricultural and Mechanical University.

Effect of processing on antioxidant contents in selected dry beans (Phaseolus spp. L.)

Abstract: Dry beans are rich sources of dietary fiber and phytochemicals such as flavonoids and phenolics. In the current study, we determined the effects of two processing methods (soaking and toasting) on total phenolics, flavonoids, proanthocyanidin and antioxidant potential by 2,2-diphenyl-1-picrylhydrazyl (DPPH) activity and ferric reducing antioxidant potential (FRAP) in selected dry beans (red kidney beans (K), black-eyed peas (B), pinto beans (P) and soy beans (S)). Total phenolics (mg/g dwb) expressed as gallic acid equivalents (GAE), total flavonoids (mg/g dwb) as catechin equivalents (CE) and proanthocyanidin expressed as leucocyanidin equivalent (mg LE/g) ranged from 3.42 to 7.21, 0.61 to 0.84 and 0.51 to 3.13 in raw beans; 3.58 to 6.94, 0.19 to 0.99 and 0.43 to 3.13 in soaked beans and 4.55 to 9.52, 0.23 to1.00 and 0.20 to 3.25 in toasted beans, respectively. FRAP (μg/g) in raw, soaked and toasted dry beans ranged from 0.00097 to 0.00424 while DPPH (T30) (%) ranged from 43.9 to 62.61. Our results indicate that processing methods (soaking and roasting) influenced total phenolic, flavonoid and antioxidant contents (DPPH, FRAP) in selected dry beans.

Changes in the Phytochemical Composition and Profile of Raw, Boiled, and Roasted Peanuts

Abstract: Peanuts are consumed mostly as processed products. Although the effect of processing on isoflavone composition of legumes has been extensively studied, there has been no such study on peanuts. The objective of this study was to evaluate the effect of processing (boiling, oil- and dry-roasting) on the phytochemical composition of peanuts. Boiling had a significant effect on the phytochemical composition of peanuts compared to oil- and dry-roasting. Boiled peanuts had the highest total flavonoid and polyphenol content. The biochanin A and genistein content of boiled peanut extracts were two- and fourfold higher, respectively. trans-Resveratrol was detected only in the boiled peanuts, with the commercial product having a significantly (p ≤ 0.05) higher concentration. Ultraviolet and mass spectrometry chromatograms for the boiled peanut extracts show the presence of four additional peaks that were not observed in the raw peanut extracts.

Effect of ultrasound on the technological properties and bioactivity of food: a review.

Abstract: This review is a comprehensive survey on the latest and more recent applications of ultrasound (US) on technological properties and bioactivity of food. Apart from a brief discussion on the fundamentals of ultrasound technology, examples have been set out on the physical effects of US on the improvement of food technological properties such as emulsification ability, solubility and texture, as well as on applications such as homogenization, viscosity alteration, extraction, drying, crystallization and defoaming. Among them, special emphasis has been placed on ultrasound assisted extraction (UAE). Nowadays, developments in ultrasonic equipment are such that it is feasible to consider commercial opportunities based on industrial-scale ultrasonic-aided extraction of bioactives, with worthwhile economics gains. Additionally, the initial restrictions associated to ultrasonically generated radicals in UAE have now been explored to enhance the functionality of some types of food. Finally, and despite the improved equipment design and the higher efficiencies of US systems currently used for other applications, a better understanding of the complex physicochemical mechanism of the action of high-intensity ultrasound and its effect on technological and functional properties of food would also contribute to reinforce the future presence of ultrasonic technologies in the food industry.

Cancer chemoprevention through dietary antioxidants: progress and promise.

Abstract: It is estimated that nearly one-third of all cancer deaths in the United States could be prevented through appropriate dietary modification. Various dietary antioxidants have shown considerable promise as effective agents for cancer prevention by reducing oxidative stress which has been implicated in the development of many diseases, including cancer. Therefore, for reducing the incidence of cancer, modifications in dietary habits, especially by increasing consumption of fruits and vegetables rich in antioxidants, are increasingly advocated. Accumulating research evidence suggests that many dietary factors may be used alone or in combination with traditional chemotherapeutic agents to prevent the occurrence of cancer, their metastatic spread, or even to treat cancer. The reduced cancer risk and lack of toxicity associated with high intake of fruits and vegetables suggest that specific concentrations of antioxidant agents from these dietary sources may produce cancer chemopreventive effects without causing...

Microencapsulation of Oils: A Comprehensive Review of Benefits, Techniques, and Applications

Abstract: Microencapsulation is a process of building a functional barrier between the core and wall material to avoid chemical and physical reactions and to maintain the biological, functional, and physicochemical properties of core materials. Microencapsulation of marine, vegetable, and essential oils has been conducted and commercialized by employing different methods including emulsification, spray-drying, coaxial electrospray system, freeze-drying, coacervation, in situ polymerization, melt-extrusion, supercritical fluid technology, and fluidized-bed-coating. Spray-drying and coacervation are the most commonly used techniques for the microencapsulation of oils. The choice of an appropriate microencapsulation technique and wall material depends upon the end use of the product and the processing conditions involved. Microencapsulation has the ability to enhance the oxidative stability, thermostability, shelf-life, and biological activity of oils. In addition, it can also be helpful in controlling the volatility and release properties of essential oils. Microencapsulated marine, vegetable, and essential oils have found broad applications in various fields. This review describes the recognized benefits and functional properties of various oils, microencapsulation techniques, and application of encapsulated oils in various food, pharmaceutical, and even textile products. Moreover, this review may provide information to researchers working in the field of food, pharmacy, agronomy, engineering, and nutrition who are interested in microencapsulation of oils.