Oxidation and Isomerization of Lycopene under Thermal Treatment and Light Irradiation in Food Processing

John Shi,Ying Wu,Mike Bryan,Marc Le Maguer 한국식품영양과학회 2002 Preventive Nutrition and Food Science Vol.7 No.2

Lycopene as a natural antioxidant may provide protection against a broad range of epithelial cancers and chronic diseases. Lycopene concentrate extracted from tomatoes can be used as functional food. Lycopene would undergo degradation via isomerization and oxidation under different processing conditions, which impact its bioactivity and reduce the functionality for health benefits. Heat and light induce lycopene oxidation and isomerization of all-trans form to cis form. The effects of thermal treatment and light irradiation on the stability of lycopene were determined. Results have shown that lycopene stability depends on the extent of oxidation and isomerization. Cis-isomers are less stable than trans-isomers. The level of cis-isomers increased as treatment time increased but only for a short period during the beginning of the treatment. The major effect of thermal treatment and light irradiation was a significant decrease in the total lycopene content. A true assessment of health benefits of lycopene concentrate depends on the lycopene content and the composition of all trans-isomers and cis-isomers.

Polyphenolics in Grape Seeds―Biochemistry and Functionality

John Shi,Jianmel Yu,Joseph E. Pohorly,Yukio Kakuda 한국식품영양과학회 2003 Journal of medicinal food Vol.6 No.4

Grape seeds are waste products of the winery and grape juice industry. These seeds contain lipid, protein, car-bohydrates, and 5 8% polyphenols depending on the variety. Polyphenols in grape seeds are mainly flavonoids, including gal-lic acid, the monomeric flavan-3-ols catechin, epicatechin, gallocatechin, epigallocatechin, and epicatechin 3-O-gallate, andprocyanidin dimers, trimers, and more highly polymerized procyanidins. Grape seed extract is known as a powerful antioxi-dant that protects the body from premature aging, disease, and decay. Grape seeds contains mainly phenols such as proan-thocyanidins (oligomeric proanthocyanidins). Scientific studies have shown that the antioxidant power of proanthocyanidinsis 20 times greater than vitamin E and 50 times greater than vitamin C. Extensive research suggests that grape seed extractis beneficial in many areas of health because of its antioxidant effect to bond with collagen, promoting youthful skin, cellhealth, elasticity, and flexibility. Other studies have shown that proanthocyanidins help to protect the body from sun damage,to improve vision, to improve flexibility in joints, arteries, and body tissues such as the heart, and to improve blood circula-tion by strengthening capillaries, arteries, and veins. The most abundant phenolic compounds isolated from grape seed arecatechins, epicatechin, procyanidin, and some dimers and trimers.

Saponins from Edible Legumes: Chemistry, Processing, and Health Benefits

John Shi,Konesh Arunasalam,David Yeung,Yukio Kakuda,Gauri Mittal,Yueming Jiang 한국식품영양과학회 2004 Journal of medicinal food Vol.7 No.1

Demand for bean products is growing because of the presence of several health-promoting components in edible bean products such as saponins. Saponins are naturally occurring compound, which are widely distributed in all cells of legume plants. Saponins, which derive their name from their ability to form stable, soaplike foams in aqueous solutions, constitute a complex and chemically diverse group of compounds. In chemical terms, saponins contain a carbohydrate moiety attached to a triterpenoid or steroids. Saponins are attracting considerable interest as a result of their diverse properties, both deleterious and beneficial. Clinical studies have suggested that these health-promoting components, saponins, affect the immune system in ways that help to protect the human body against cancers, and also lower cholesterol levels. Saponins decrease blood lipids, lower cancer risks and lower blood glucose response. A high saponin diet can be used in the inhibition of dental caries and platelet aggregation, in the treatment of hypercalciuria in humans, and as an antidote against acute lead poisoning. In epidemiological studies, saponins have been shown to have an inverse relationship with the incidence of renal stones. Thermal processing such as canning is the typical method to process beans. The study reviews the effect of thermal processing on the characteristics and stability of saponins in canned bean products. Saponins are thermal sensitive. During soaking and blanching, portions of saponins are dissolved in water and lost in the soaking, washing and blanching liquors. An optimum thermal process can increase the stability and maintain the saponins in canned bean products, which is useful for assisting the food industry to improve thermal processing technology and enhance bean product quality.

Lycopene

John Shi 한국식품과학회 2002 Food Science and Biotechnology Vol.11 No.5

Bioavailability of Lycopene from Tomato Products

John Shi,Laura MacNaughton,Yukio Kakuda,William Bettger,David Yeung,Yueming Jiang 한국식품영양과학회 2004 Preventive Nutrition and Food Science Vol.9 No.1

Tomatoes and tomato products are the major source of lycopene in the diet. The bioavailability of lycopene is different in raw tomatoes compared to processed tomato products. This is due to the chemical and physical properties of the different lycopene isomers. All-trans-lycopene is found in raw tomatoes and is a poor bioavailable source, whereas, processed tomato products are more bioavailable because they contain more cis-isomers. Heat and mechanical processing of tomatoes induces rupture of the cell walls, thereby releasing lycopene from its food matrix. Heat processing also induces cis-trans isomerization and disrupts protein-carotenoid complexes. Many dietary components also impact lycopene bioavailability, like the amount and type of fat present with the intake and processing of tomato products, the amount and type of fiber present, and the interaction between carotenoids. Fundamentally, anything that enhances formation and incorporation of lycopene in bile acid micelles increases bioavailability, and the opposite is true in that anything that interferes with micelle formation decreases bioavailability.

Bioavailability and Efficiency of Tea Catechins as an Antioxidant

John Shi 한국식품영양과학회 2002 Preventive Nutrition and Food Science Vol.7 No.3

Tea is a pleasant, popular and safe beverage in the world. During the past decade, epidemiological studies have shown that tea catechins intake is associated with lower risk of cardiovascular disease. Tea provides a dietary source of health-promoting components to help humans reduce a wide variety of cancer risks and chronic diseases. The antioxidative activity of tea-derived catchins has been extensively studied. The antioxidant effect is a synergistic action between catechins e.g. EGCG, EGC, ECG, EC, pheophytins a and b, and other components in tea leaves, which are more bioavailable for human body. Green tea has a higher content of catechins than other kinds of tea. Green tea extract with hot water has high potential and more efficiency to reduce cancer risk than any other tea products or pure EGCG. Protein, iron, and other food components may interfere with the bioavailability of tea catechins. Interaction of catechins with drug affects the cancer-preventive activity of some cancer-fighting medication. Further studies are required to determine the bioavailability of tea catechins and cancer-preventive functionality.

Bioavailability of Lycopene from Tomato Products

Shi, John,Naughton, Laura-Mac,Kakuda, Yukio,Bettger, William,Yeung, David,Jiang, Yueming The Korean Society of Food Science and Nutrition 2004 Preventive Nutrition and Food Science Vol.9 No.1

Tomatoes and tomato products are the major source of lycopene in the diet. The bioavailability of lycopene is different in raw tomatoes compared to processed tomato products. This is due to the chemical and physical properties of the different lycopene isomers. All-trans-lycopene is found in raw tomatoes and is a poor bioavailable source, whereas, processed tomato products are more bioavailable because they contain more cis-isomers. Heat and mechanical processing of tomatoes induces rupture of the cell walls, thereby releasing lycopene from its food matrix. Heat processing also induces cis-trans isomerization and disrupts protein-carotenoid complexes. Many dietary components also impact lycopene bioavailability, like the amount and type of fat present with the intake and processing of tomato products, the amount and type of fiber present, and the interaction between carotenoids. Fundamentally, anything that enhances formation and incorporation of lycopene in bile acid micelles increases bioavailability, and the opposite is true in that anything that interferes with micelle formation decreases bioavailability.

Bioavailability and Efficiency of Ten Catechins as an Antioxidant

Shi, John The Korean Society of Food Science and Nutrition 2002 Preventive Nutrition and Food Science Vol.7 No.3

Tea is a pleasant, popular and safe beverage in the world. During the past decade, epidemiological studies have shown that tea catechins intake is associated with lower risk of cardiovascular disease. Tea provides a dietary source of health-promoting components to help humans reduce a wide variety of cancer risks and chronic diseases. The antioxidative activity of tea-derived catchins has been extensively studied. The antioxidant effect is a synergistic action between catechins e.g. EGCG, EGC, ECG, EC, pheophytins a and b, and other components in tea leaves, which aye more bioavailable for human body. Green tea has a Higher content of catechins than other kinds of tea. Green tea extract with hot water has high potential and more efficiency to reduce cancer risk than any other tea products or pure EGCG. Protein, iyon, and other food components may interfere with the bioavailability of ten catechins. Interaction of catechins with drug affects the cancer-preventive activity of some cancer-fighting medication. Further studies are required to determine the bioavailability of tea catechins and cancer-preventive functionality.

A study of internal wave influence on OTEC systems

Shi, Shan,Kurup, Nishu V.,Halkyard, John,Jiang, Lei Techno-Press 2013 Ocean systems engineering Vol.3 No.4

Ocean Thermal Energy Conversion (OTEC) systems utilize the temperature difference between the surface water and deep ocean water to generate electrical energy. In addition to ocean surface waves, wind and current, in certain locations like the Andaman Sea, Sulu Sea and the South China Sea the presence of strong internal waves may become a concern in floating OTEC system design. The current paper focuses on studying the dependence of the CWP hydrodynamic drag on relative velocity of the flow around the pipe, the effect of drag amplification due to vortex induced vibrations and the influence of internal waves on the floating semi and the cold water pipe integrated OTEC system. Two CWP sizes are modeled; the 4m diameter pipe represents a small scale prototype and the 10m diameter pipe represents a full commercial size CWP. are considered in the study.

Pelletized SiO2-supported La0.5Ba0.5FeO3 for conversion of CO2 to CO by a reverse water-gas shift chemical looping process

Hanzhong Shi,Venkat R. Bhethanabotla,John N. Kuhn 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.118 No.-

Perovskite oxides, such as La0.5Ba0.5FeO3 (LBF), are promising materials for converting CO2 to CO throughlow-temperature reverse water–gas shift chemical looping (RWGS-CL). To transition toward industrialization,this study focused on forming perovskite-oxide/silica composite pellets (25 wt% LBF) with sufficientlyhigh crushing strength, with materials prepared by extrusion and tableting methods. X-rayfluorescence (XRF) and diffraction (XRD) confirmed that the resulting material is 26.6 wt% LBF on SiO2with a combined structure of LBF and SiO2 components. Temperature-programmed reduction (TPR)and oxidation (TPO) experiments revealed that CO2 is converted to CO at 550 C by LBF/SiO2 pellets,higher than LBF by 50 C. CO2 chemisorption was determined to be 62.2 lmol/gLBF. DRIFTS-MS experimentsconfirmed that adsorbed CO2 is dissociated to CO. High material stability is proven by longtermRWGL-CL experiments combined with XRD and XPS. The CO2 to CO yields were 2.21, 2.41, and2.35 mmol/gLBF of 10 mm tableting pellets, 6 mm tableting pellets, and extrusion pellets, respectively. Deactivated pellets are able to be regenerated by air thermal treatment following intentional reduction. All pellets showed stable redox properties in 50 cycles of semi-batch reactor experiments, indicating thatLBF/SiO2 pellets are candidate materials for further scale-up evaluation.