Ken Lee

The Ohio State University | OSU · Department of Food Science and Technology

The objectives of the current study were to investigate the fate of microbial indicators [aerobic plate counts (APC), total coliforms (TC), and lactic acid bacteria (LAB)] in commercial salted napa cabbages during storage conditions at different temperatures (5, 22, and 30 °C, for up to 72 h) and to develop a predictive growth model using the modif...

Food processing alters the physicochemical state of soy which can enhance chemical and enzymatic conversion of isoflavones to their aglycone forms. This study investigated the role of β-glycosidase from processed soy-ingredient mixture (SIM) or almonds, and examined the impact of isoflavone composition in mediating conversion to aglycone. β-Glycosi...

Objectives: On December 2013, the US FDA proposed a rule stating that manufacturers must provide data to demonstrate that antibacterial soap is more effective than plain soap or water. The objective of the present study was to examine the in vitro and in vivo bactericidal effect of triclosan (the most widely used antiseptic agent in soap) in soap....

Raw eggs are a potential health hazard and a new federally approved process uses ozone to maintain freshness while ensuring safety. The impact of an ozone process on the flavor, color, and shell integrity of eggs must be known for market acceptance. The visual perception and consumer acceptance of full commercial scale ozone-pasteurized eggs are re...

Norovirus remains the leading cause of foodborne illness, but there is no effective intervention to eliminate viral contaminants in fresh produce. Murine norovirus 1 (MNV-1) was inoculated in either 100 ml of liquid or 100 g of food. The inactivation of MNV-1 by electron-beam (e-beam), or high-energy electrons, at varying doses was measured in mode...

This study compared the efficacies of two traditional with two experimental sanitizers for use in tableware cleaning operations in restaurants and foodservice operations. This was done by investigating the maximum number of cleaning cycles that a single recommended quantity of each sanitizer could treat and still produce a 5-log bacterial reduction...

During the past decade there were more than 50 reported outbreaks involving leafy green vegetables contaminated with foodborne pathogens. Leafy greens, including cabbage, are fresh foods rarely heated before consumption, which enables foodborne illness. The need for improved safety of fresh food drives the demand for nonthermal food processes to de...

About 1.2 billion pounds of peanut butter are consumed annually in the United States. In 2008 to 2009, an outbreak involving Salmonella Typhimurium in peanut butter led to a recall of over 3900 products by over 200 companies. More than 700 people became sick, 100 were hospitalized, and 9 people died from this outbreak. This study examines the effic...

The survival of enteric pathogens on vegetable leaves improves due to presence of phytopathogens. Phytopathogen damage alters the microenvironment on the leaf surface. The objective of this study was to identify differences in sugar concentrations in tomato leaves damaged by biotropic plant pathogens and determine if these differences affect Escher...

Unlabelled: Ozone-based processing is a novel technology with potentially fewer adverse effects than in-shell thermal pasteurization of eggs. There are no consumer acceptance studies published on ozone-treated eggs. This study examines consumers' ability to detect changes between ozone-treated, thermal-treated, and fresh untreated eggs. Consumers...

  A focus group with an educational component was used to help initiate a new research hypothesis. Early-stage development of a new tamper-evident invention was improved with input from a consumer focus group. The focus group comprised consumers who were shown several tamper-evident devices, including a new color-changing cap under active developme...

The ecology of the vegetable leaf surface is important to the survival of enteric pathogens. Understanding changes in ecological parameters during the preharvest stages of production can lead to development of approaches to minimize the hazard of contamination of fresh fruits and vegetables with foodborne pathogens. In this study, survival levels o...

Increasing evidence indicates that ozone gas is effective against Salmonella on and within shell eggs. However, information on the penetration of ozone across egg shell is limited. In this study, whole hen egg shells, filled with indigotrisulfonate solution (OD600 ∼1), were exposed to ozone gas (12–14% wt/wt O3 in O2) at 1.5 liters/min and atmosphe...

Pathogens on edible plants present a significant potential source of human illness. From 1991 to 2002, 21% of Escherichia coli O157:H7 outbreaks were from produce-related sources. E. coli O157 and other enteric bacteria can contaminate the surface of edible plants both pre- and postharvest. Some pathogens do not survive on the leaf surface or are r...

The effects of baking processes on the chemical forms of iron were investigated. Various iron enrichment sources were shown to exist initially in distinct chemical forms. These sources were then added to flour and baked as biscuits, and the resulting distribution of iron forms, or “iron profile,” measured. The baking generated large amounts of inso...

Apparent absorption of calcium by rats from cottage cheese was very efficient under the conditions tested. However, overall calcium retention and, to a lesser extent, bone calcium content increased with each increment in dietary calcium. Despite sensitivity of the model to variation in calcium intake, no effect of guar gum on calcium utilization wa...

Lipid microcapsules of FeSO4, alone or with ascorbic acid, and FeCl3, were developed to fortify cheese and other high moisture foods with iron. Varying lipid coat composition and amount of core iron solution optimized their stability. A high melting fraction of milk fat (m.p. 43.5°C) was oxidized by iron and was thus unsuitable as coat material. Mi...

Iron, copper and zinc but not magnesium were bound by neutral (NDF) and acid (ADF) detergent fiber obtained from cooked pinto beans. Iron binding increased with higher pH, higher iron concentration, higher fiber concentration and smaller fiber particle size. Maximum binding of iron was at pH 6.5 and minimal binding at pH 4.0 for both NDF and ADF. A...

The chemical forms of iron, calcium, magnesium and zinc were quantified in black, oolong, green and instant black tea infusions. Iron was least soluble in black tea (69%) and most soluble in instant black tea (100%). Calcium was least soluble in green tea (46%) and instant black tea (35%). Almost all magnesium and zinc (89%-98%) were soluble in all...

Phytic acid was quantified using a tetrabutylammonium-formate ion pair on an octadecyl column in HPLC. Unlike previous methods, phytic acid eluted significantly later than the dead volume. Good separations were possible with a linear response up to 40 micrograms and a sensitivity of 0.002 micrograms phytic acid. Results with this method are compati...

ABSTRACTA method for the simultaneous quantification of the various forms of iron added or endogenous to foods has been developed. The total, elemental, and soluble iron are determined with minimal pre-treatment by atomic absorption spectrophotometry. The iron valences and complexed iron are measured spectrophotometrically using the bathophenanthro...

The effect of thermal processing on endogenous and added iron in canned spinach puree was investigated. Eight different sources of iron were evaluated for their distribution of iron forms, or “iron profile” after four treatments. The treatments included: control, unprocessed, processed, and processed with ascorbate. Iron endogenous to raw spinach w...

Various iron sources used in food fortification are analysed for their distribution of iron forms, or “iron prof”le,” using previously described methodology. The effect of reaction with a beverage containing ascorbate, concomitant with freeze and spray drying processes, are investigated. The iron profile of certain sources are shown to change as a...

Iron was bound by neutral (NDF) and acid (ADF) detergent fibers extracted from cooked pinto beans (Phaseolus vulgaris). Soluble iron (total iron minus bound iron) in the presence of NDF was increased from 13.11 ± 5.08 to 35.58 ± 9.20% and from 22.22 ± 164 to 29.98 ± 0.96% when 1.17 and 1.38 ppm (18.4 and 21.4 PM) of copper and zinc were added, resp...

Methods for quantitative estimation of nitrate and nitrite were compared. Levels of these ions were measured in vegetables and grain products and effects of processing on nitrate and nitrite levels in carrots were measured. These data allow more accurate estimation of ingestion levels and suggest means to reduce exposure to these ions. High perform...

Chemical availability of calcium was measured with and without simulated digestion to determine processing effects. Available calcium was low in spinach and significantly higher in skim milk and whole milk, consistent with their known bioavailabilities. In nondigested processed milk it was significantly higher for whole milk than for skim milk. How...

Light-induced generation of two cholesterol oxidation products, 7α- and 7β-hydroxycholesterol, was measured in an egg nog mix using an improved isolation procedure and high performance liquid chromatography (HPLC). Dry egg nog mix was exposed continuously to fluorescent light at room temperature for 90 days. The 7α-hydroxycholesterol was formed in...

Solubility, valence, and complexation of iron were measured in four different processed meats cured with or without 156 ppm sodium nitrite and with or without 550 ppm sodium erythorbate (d-isoascorbate). Nitrite caused less ionic iron and erythorbate caused more ferrous and soluble iron after a conventional curing process. Heme iron levels were unc...

ABSTRACTA high performance liquid chromatographic method (HPLC) was compared to cadmium reduction-Griess (Cd-Griess). Nitrate and nitrite were measured in fresh and cured meats. Nitrate levels by HPLC ranged from 6.2 to 26.7 nmol/g in fresh meats and from 124 to 3018 nmol/g in cured meats. Nitrate contents by HPLC were significantly higher (p<0.05)...

Aqueous dispersions of soluble hydrocolloids replaced lipids in process cheese spreads. About 40% and 50% fat reduction was obtained relative to a control cheese spread containing 25% fat by increasing moisture to 62% and 68%, respectively, and eliminating a portion of fat from the formulation. Xanthan, λ-carrageenan, three types of high-methoxyl p...

this report details how we taught SPICE about transmission lines and verified their accuracy. In addition it describes the sizeable library of components from which we assembled simulations

Interactions of mammalian pancreatic cholesterol esterases from pig and rat with a family of aryl carbamates CnH2n+1NHCOOAr [n = 4-9; Ar = phenyl, p-X-phenyl (X = acetamido, bromo, fluoro, nitro, trifluoromethyl), 2-naphthyl, 2-tetrahydronaphthyl, estronyl] have been investigated, with an aim of delineating the ligand structural features which lead...

To compare the efficacy of three commercially available oral lactase preparations in adults with lactose intolerance. Design--Prospective, randomized, placebo-controlled trial. Setting--Outpatient study in a General Clinical Research Center. Subjects--Ten lactose-intolerant healthy volunteers were challenged with ice cream containing 18 g of lactos...

Chemically measured calcium was correlated with bioavailability of calcium by rat bioassay. Calcium-fortified cottage cheese was evaluated by both chemical and bioassay tests. Cheese was fortified at four levels of calcium with or without added guar to increase acceptability. Chemical tests on laboratory digests and non-digested samples were by two...

Many researchers report substantial reductions in iron availability when dairy products are consumed with solutions of iron. Yet other studies indicate that dairy products have little effect on iron availability when added to complex meals. The conflicting data may be due to differences in the technique used to measure availability, species of anim...

Several hydrocolloids masked bitter tasting Ca salts added to cottage cheese. Cottage cheese dressing was partially replaced by hydrocolloid and fortified with calcium chloride, calcium phosphate, calcium lactate, calcium carbonate, or calcium citrate and evaluated for bitterness at equal calcium levels. Calcium lactate was the least bitter salt an...

During the past decade, there has been a great expansion in the development of microencapsulated food ingredients. Microencapsulation is a process of entrapping solid particles, droplets of liquids and gases in thin polymer coats. Microencapsulation can suppress the volatility, flavor, odor and reactivity of food ingredients. Microcapsule contents...

Iron absorption in the presence of varying amounts and sizes of dietary fiber was measured. A method using non-everted rat intestinal segments perfused in oxygen was refined. Neutral detergent fiber (NDF), a component of dietary fiber, was extracted from cooked pinto bean (Phaseolus vulgaris). The NDF did not affect iron absorption in intestinal se...

Chemical forms of iron, calcium, magnesium and zinc (mineral profiles) were measured in brews of regular and decaffeinated instant coffee and diets containing these coffees. Iron, calcium and magnesium were highly soluble (90–98%) in brews of both coffees and zinc could not be detected. All ionic iron was in the ferric state and 40–48% of total iro...

Chemical forms of iron, calcium, magnesium, zinc and copper were measured in rat diets containing 0–3.5% instant black tea. As instant tea in diets increased, more iron was soluble and ionic. Diets containing tea had more complexed iron than without. Calcium had low solubility (10–12%) while almost all magnesium (92–98%) was soluble in all diets. S...

Methods for the extraction of cholesterol oxides from meats were studied. A dry column technique for the extraction of sterols was found to be more rapid and convenient than conventional chloroform-methanol extraction. An overall yield of 32·0% and 23·6% for radiolabelled cholesterol and cholesterol oxides, respectively, was obtained after dry colu...

Nitrate balance was measured in nine men consuming a fixed daily diet with constant nitrate (570 mumol/day), varying nitrite (18 to 150 mumol/day), and varying erythorbate levels. Nitrite and erythorbate were added to meat that was then cured and frozen until consumption. All diets were consumed by each subject for 17 days each. Average daily urina...

A model for studying the effect of cholesterol autoxidation products on membrane function was developed. Eight cholesterol autoxidation products were tested for their effect on growth of Mycoplasma gallisepticum. None gave better growth than cholesterol. When substituted for cholesterol in the growth medium, 6-ketocholesterol and cholesterol triol...

The bioavailability of zinc and copper from meats cured with erythorbate and/or nitrite was evaluated. Iron-depleted rats were fed six test diets that contained as protein sources: uncured meat, meat cured with erythorbate, meat cured with nitrite, meat cured with nitrite and erythorbate, lactalbumin, and lactalbumin supplemented with iron to the l...

Potato chips and french fries were analyzed by high performance liquid chromatography and thin layer chromatography for cholesterol and (β-sitosterol oxidation products. Chips stored for 150 d at 23°C in unopened foil bags contained no detectable sitosterol oxidation products, but those held at 40°C contained 7α-hydroxysitosterol, 7β-hydroxysitoste...

Butteroil samples bleached with benzoyl peroxide (BP) and 17 commercial cheeses were screened for oxidized sterols by thin layer chromatography (TLC). Ungrated cheeses made from bleached milk and freshly bleached butteroil contained no detectable oxidized sterols. Oxidized sterols were detected in stored, bleached butteroils and in grated cheeses....

Picric acid (2, 4, 6-trinitrophenol) was reacted with sterol epoxides to form a chromophore with absorption maxima at 350 and 410 nm, which follow Beer's law. Linearity was obtained up to 0.2 mg/ml with a sensitivity of 2 μg of cholesterol α-epoxide/ml. Optimum conditions included a 24-h reaction at 23°C, a 150 + M/M excess of picric acid over ster...

Erythorbate was measured in nitrite-cured meats using ion-paired HPLC. With tetrabutylammonium formate as the ion pair, good separations were obtained with a linear response' up to 300 ppm of erythorbate. Recoveries were complete and agreed with values obtained by titration with 2,6-dichloroindophenol. The method is specific and free from interfere...

The effect of food processing on the bioavailability and chemistry of iron was reviewed with emphasis on research employing an iron profile analysis. Iron profiling, a measurement of iron valence, solubility, and complexation, identified chemical changes which took place in drying, baking and retort processes. Agreement between iron profile and ani...

An international program has been underway in the Kosovo Region of Yugoslavia to characterize the environmental problems associated with a commercial Lurgi coal gasification system. The gasification plant consists of six pressurized oxygen blown gas generators with an associated gas cooling system, a tar and oil separation plant, a Rectisol acid-ga...

The effect of food processing on the biological availability of iron in iron-fortified foods is critically reviewed. Studies on changes in the chemistry of the iron in processed foods are examined. Various iron sources currently used in food fortification in the U.S. are defined with emphasis on their biological availabilities under various conditi...