Karen Schaich

• Sc.D.
• Professor (Associate) at Rutgers, The State University of New Jersey

Immense gains in understanding of mechanisms and effects of lipid oxidation have been achieved in the nearly 90 years over which lipid oxidation has been an active research focus. Even so, the substantial questions still being raised about lipid oxidation in this special issue show clearly that missing pieces remain and must be considered for full...

Lipid autoxidation poses a significant problem for stabilizing sensory quality, nutritional value, and chemical safety of lipid containing foods. Peroxide value and volatile carbonyls are the most measured markers to assess oxidation, but products such as epoxides and alcohols are now being identified and quantified in foods. The mechanisms and con...

Phenolic antioxidants are well-known to inhibit lipid oxidation by quenching radicals. This slows propagation and is a key component of antioxidant action. However, total antioxidant effects reach far beyond early radicals. Phenolic compounds also inhibit initiation by binding metals and quenching singlet oxygen, cause shifts in oxidation pathways...

Toxicity of food components is now under intense scrutiny as the public has become increasingly concerned about the safety of our food supply. Products of lipid oxidation and thermal degradation have long been suspected as potential toxins when consumed in the diet, and numerous changes induced by lipid oxidation products have been reported. Howeve...

After lying in the doldrums during the no/low fat era, lipid oxidation is once again attracting intense interest for its effects on food quality, stability of personal care products, impairment of functional properties, and nutrition in foods, as well as toxic potential in tissues. Advanced analytical methods now detect lipid oxidation products wit...

Figure S1. Perceived intensity of fatty and creamy attributes in safflower oil emulsions with or without added oleic acid in East Asians. Figure S2. Perceived intensity of fatty and creamy attributes in safflower oil emulsions with or without added oleic acid in Caucasians.

Previous studies demonstrate humans can detect fatty acids via specialized sensors on the tongue, such as the CD36 receptor. Genetic variation at the common single nucleotide polymorphism rs1761667 of CD36 has been shown to differentially impact the perception of fatty acids, but comparative data among different ethnic groups are lacking. In a smal...

The potential for using extracts of press residues from black, green, red and white currants and from sea buckthorn berries as sources of antioxidants for foods use was investigated. Press residues were extracted with ethanol in four consecutive extractions, and total Folin-Ciocalteu (F-C) reactive material and authentic phenolic compounds were det...

This work evaluated the ability of an innovative and practical package label made from biobased polymers impregnated with sodium chlorite and citric acid to generate and release chlorine dioxide (ClO2) at levels sufficient to inactivate pathogenic bacteria on packaged fresh produce. The concentrations of generated ClO2 by these labels were dependen...

Lipid oxidation has always been viewed as a simple free radical chain reaction with straightforward sequence of radicals → hydroperoxides → products. The first paper in this series proposed that alternate reactions of lipid peroxyl and alkoxyl radicals compete with hydrogen abstraction to make the process much more complex. This article provides ex...

There is need for in-package anti-microbial technology to control microbial growth on packaged fresh food. This research evaluated the feasibility of delivering chlorine dioxide (ClO2) via package labels made of synthetic polymers extruded with citric acid (CA) and sprayed with sodium chlorite. Heat pressing facilitated ClO2 generation and moisture...

During nearly 20 years of the low-/no-fat era, lipid oxidation was essentially forgotten as a stability problem. Now, the era of healthy fats focuses on reformulating foods with highly unsaturated (polyunsaturated) fatty acids (PUFAs). PUFAs are essential – they cannot be synthesized by humans and they are required for many physiological processes...

Assays developed to measure radical scavenging ability of natural compounds have been used as a basis for ranking and recommending best foods for consumption. However, assays often were adapted for screening assays with inadequate consideration of reaction chemistry, particularly kinetics. Recent research results raise serious questions about the c...

Accelerated solvent extraction (ASE) was evaluated for extracting lipids from baked and extruded dry pet foods to determine factors controlling extraction efficiency and effects on lipid oxidation. Hydroperoxide decomposition and new lipid oxidation were minimal at 40 A degrees C but increased at higher extraction temperatures without increasing yi...

Kinetics and stoichiometry of reactions between 2,2-diphenyl-1-picrylhydrazyl (DPPH) stable radical and 25 antioxidant compounds with different structure, molecular weight, number of -OH groups, and redox potential were investigated by recording loss of DPPH• absorbance at 515 nm continuously for 10 minutes. A series of antioxidant concentrations w...

Oxidizing lipids transfer damage to proteins. Such damage degrades food quality beyond production of rancid flavors and odors.  Lipid co-oxidation of maize proteins in fried tortilla chips causes protein surface modifications and formation of very large protein aggregates with free radical and disulfide crosslinks, while lipid co-oxidation of prot...

• Oxidizing lipids transfer damage to proteins. Such damage degrades food quality beyond production of rancid flavors and odors. • Lipid co-oxidation of maize proteins in fried tortilla chips causes protein surface modifications and formation of very large protein aggregates with free radical and disulfide crosslinks, while lipid co-oxidation of pr...

This chapter focuses on arguing for new approaches and seeks to change how lipid oxidation analyses are viewed and used to attain more complete and accurate information. Lipid oxidation presents several distinctive challenges for analysis: (1) providing quantitative, reproducible analyses that accurately reflect oxidation chemistry; (2) tracking mu...

This chapter highlights that the intention of the chapter is to challenge anyone concerned with lipid oxidation-whether in fundamental chemical research, food quality deterioration, pathology or toxicology, cell signaling, or any other application-to think beyond hydrogen abstraction in established free-radical chain reactions and to consider other...

Reaction kinetics in the Trolox Equivalent Antioxidant Capacity (TEAC) Assay between ABTS(+•) [2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) cation radical] and compounds with different structure, molecular weight, number of -OH groups, and redox potential were investigated by recording loss of ABTS(+•) absorbance (734 nm) continuously ove...

The chemical diversity of natural antioxidants (AOXs) makes it difficult to separate, detect, and quantify individual antioxidants from a complex food/biological matrix. Moreover, the total antioxidant power is often more meaningful to evaluate health beneficial effects because of the cooperative action of individual antioxidant species. Currently,...

Introduction Composition and nutritional characteristics of dried cranberry powder Natural antioxidants in dried cranberry powder Health effects of dried cranberry powders Food applications of dried cranberry powders Conclusions References

The antioxidant effects of sesamol films were evaluated using a food simulant (linoleic acid) and a real food (oat cereal). Sesamol was melt blended with high density polyethylene, linear low density polyethylene and ethylene-vinyl acetate resins using co-extrusion to produce sesamol films of multilayer structure; for comparison, films containing b...

Evidence from literature has shown that compared with instant addition, slow release of antioxidants has some advantages to inhibit lipid oxidation and extend shelf life of food products. In this paper, the hypothesis that there is a range of release rates of antioxidants which could provide the maximum extension of induction period for lipid oxida...

For the past few decades, research on lipid oxidation mechanisms has been rather stagnant due to a pervasive attitude that reactions of lipid oxidation were well understood, so only tailoring applications of basic knowledge to stabilize individual systems was needed. This simplistic approach worked during the low fat/no fat era because there was li...

Lipid oxidation is the major chemical reaction limiting the shelf-life of foods, and it also contributes to a wide range of pathologies, including aging and cancer. This chapter provides an interesting new perspective on broad aspects of lipid oxidation. It first reviews details of lipid oxidation reactions and mechanisms in the context of traditio...

Preparation and properties of composite films from gelatin and low-methoxyl pectin from simultaneous reversible and permanent polyion-complex hydrogels are presented. Ionic interactions between positively charged gelatin and negatively charged pectin produce reversible physical hydrogels with homogeneous molecular arrangement that improve both mech...

Labels and Labeling Machinery Laws and Regulations, United States Leak Testing Life-Cycle Assessment Light Protection from Packaging Lipid Oxidation: Chemical Stabilization Liquid-Crystalline Polymers, Thermotropic Logistical/Distribution Packaging Bibliography

Emerging evidence is elucidating how non-nutrient phytochemicals underlie the health promotion afforded by fruits and vegetables. This review focuses on Vaccinium macrocarpon, the American cranberry, compiling a comprehensive list of its known phytochemical components, and detailing their prevalence in cranberry fruit and its products. Flavonoids,...

Development of packaging materials from renewable resources has for a long time been desirable for sustainability reasons, but with recent explosion in prices of petroleum products, this now becomes also more economically viable. This paper shows how fundamental chemistry underlying three forms of hydrogels—physical hydrogels, chemical hydrogels, a...

Controlled release packaging offers significant potential for extending shelf life of foods, cosmetics and pharmaceuticals by slowly releasing antioxidants and antimicrobials over time to replenish consumed active components originally present. However, release rates attainable with current packaging are too fast or too slow for practical use and d...

Teaching any science is a challenge because fundamental concepts are not intuitive for most students and explanations are not easy to connect to real experiences. Hence, “facts” are memorized for exams and, with luck, most students will remember a little of the information a few weeks after the exam. Hopefully, some may remember enough to use in la...

Bioavailability of glycosylated flavonoids is thought to be influenced by sugar moiety specificity. We evaluated the bioavailability, metab. and distribution of the main cranberry flavonol glycosides administered via oral gavage in mice. Quercetin- 3- galactoside (Q- 3- gal) , quercetin- 3- glucoside (Q- 3- glc) , and their putative metabolites wer...

Extruded corn-soy products developed for the US AID Food for Peace program contain high levels of lipids (about 12%) and vitamins and minerals, including oxidation-sensitive vitamins A and C and iron. Because lipid stability is probably the most important factor in maintaining long-term storage stability of these products, being able to analyze lip...

Cranberry fruit is a rich source of polyphenols, and has shown biological activities against Streptococcus mutans. In the present study, we examined the influence of extracts of flavonols (FLAV), anthocyanins (A) and proanthocyanidins (PAC) from cranberry on virulence factors involved in Streptococcus mutans biofilm development and acidogenicity. P...

Lipid oxidation or rancidity is clearly the major challenge for stabilizing specialty oils, particularly since oils with special nutraceutical properties have predominantly polyunsaturated fatty acids. While there is relatively little data yet available regarding oxidation of specialty oils per se, all oils follow the same fundamental processes, mo...

As pharmaceutical and nutraceutical interest in natural antioxidants has skyrocketed in the past few years, a plethora of methods have come into common use for screening antioxidant content of natural materials and for comparing antioxidant activity of various classes of compounds. These include ORAC (Oxygen Radical Absorbance Capacity), TEAC (Trol...

Lipid oxidation has long been accepted as a classic free radical chain reaction mechanism with initiation, propagation, and termination stages. This view is not inaccurate, but it is incomplete. Initiation is generally treated as if it was spontaneous or random, but in reality, radical initiation is quite specific and varies with the source. Simila...

Methods available for the measurement of antioxidant capacity are reviewed, presenting the general chemistry underlying the assays, the types of molecules detected, and the most important advantages and shortcomings of each method. This overview provides a basis and rationale for developing standardized antioxidant capacity methods for the food, nu...

Researchers from Rutgers University and Clemson University have collaborated to develop a concept of using smart blending to generate functional packaging films for the controlled release of active compounds such as antimicrobials, antioxidants and flavour compounds to extend the shelf-life of food. In this paper, literature results are reviewed to...

Cereal Chem. 80(6):791–798 Antibodies specific for wheat proteins were used to identify protein fractions modified during extrusion of Hard Red Spring wheat flour (14% protein) under four different combinations of extrusion conditions (18 and 24% feed moisture and 145 and 175°C die temperature). Antibody binding was assessed on immunoblots of prote...

Although some roles for free radicals in foods have been proposed, relatively little research to document suspected radicals has been undertaken. EPR is a highly specific and sensitive technique for direct detection of free radicals; application of EPR to foods can reveal important information about radical reactions that may be responsible for foo...

Low temperature EPR studies were conducted on beef cubes thermallyprocessed in MRE-type flexible pouches to observe release of "free" iron or otter metals that could contribute to lipid oxidation and meat quality degradation during storage. Instead of detecting unbound iron, the surprising result was detection of NO adventitiously trapped by hemes...

To better understand, at the molecular level, protein behavior in reduced-water environments, lysozyme was labeled with TEMPO-todoacetamide (TEMPO-IA), a small amphiphilic nitroxide spin label, and equilibrated over phosphorus pentoxide or saturated salt solutions to & Ml range (0-1.0) of water activities. Changes in solvent environment detected by...

EPR has detected free radicals in extruded cornmeal, wheat flour, potato granules, and plantain flour. The g-values in all cases are in the range g=2.0055-2.0060, indicating nitrogen-centered radicals, most likely on proteins. Extensive EPR and chemical analyses have shown that the radicals are integrally involved in the chemical changes leading to...

Extruded corn-soy products developed for the US AID Food for Peace program contain high levels of lipids (about 12%) and vitamins and minerals, including oxidation-sensitive vitamins A and C and iron. Because lipid stability is probably the most important factor in maintaining long-term storage stability of these products, being able to analyze lip...

Cereal Chem. 76(5):748–755 Electron paramagnetic resonance (EPR) spectroscopy was used to study free radical production in hard red wheat flours extruded according to a two-level fractional factorial experimental design (11 and 14% protein content, 160 and 185°C, 16 and 20% moisture, 300 and 500 rpm screw speed, and mass flow rate of 225 and 400 g/...

Cereal Chem. 76(5):756–763 Effects of twin-screw extrusion conditions on wheat flour proteins were studied, using a two-level fractional factorial experimental design (11 and 14% protein content, 160 and 185°C, 16 and 20% moisture, 300 and 500 rpm screw speed, mass flow rate of 225 and 400 g/min). Total pro-tein detectable by solid-phase bicinchoni...

Is diversity the newest social fad, or is it the American/deal finally coming of age? In a country originally settled by many different peoples seeking the right to be divergent thinkers, those very differences have paradoxically been converted into the norm in the great melting pot.

Single (SSB) and double strand breaks (DSB) in supercoiled plasmid DNA pBR322 reacted with linoleic acid hydroperoxides (LOOH) were followed by agarose gel electrophoresis to obtain definitive information about factors affecting LOOH interaction with DNA. In water, LOOH induced extensive DSB, which were metal mediated and increased with incubation...

Addition of cysteine as a free radical scavenger during extrusion markedly affected physical and chemical properties of wheat flour extrudates. Radial expansion at the die decreased in linear extrudates and longitudinal expansion through surfaces cut at the die increased, reflecting weakened dough strength. Cell size decreased, cell walls thinned,...

We present a simple method for the rapid preparation of veratryl alcohol by reducing commercially available veratraldehyde with sodium borohydride resulting in high-purity veratryl alcohol. The lag period in the activity of lignin peroxidase from Phanerochaete chrysosporium that is associated with use of commercial preparations of the substrate is...