Industrial Applications of Selected JFS Articles

Who would have thought, as a food technologist in the 1970's and 80's, that the nutrition content and safety of foods would begin to take center stage. Foods still have to taste good, and the general public has embraced fresh foods with a fervor that has driven safety into question. But the following edge of the Boomers and Generation X want food to serve as a bulwark against aging and as a method of retaining good health. They demand it, but still want to consume food that tastes very good. Fortunately, their sense of taste is such that it's generally possible to enhance nutrition in foods and not have it rejected. But tasting good isn't enough, and neither is providing food that is convenient to the utmost. Products sell better when they make a contribution to well-being. That perception changes often, and formulators have to be up on the latest, and have alternatives available when the science takes a rapid U-turn.

Studies Provide Knowledge about Lycopene Forms

During the early days of discovery of lycopene as an antioxidant in tomatoes, there was a lot of quasi-information about the forms of the factor, and how it reacted to processing. Lycopene is a powerful biological antioxidant, and its delivery to humans may be more complex than previously believed. Cis-lycopene isomers are more bioavailable than the all-trans isomers and are more efficiently absorbed. Tangerine tomatoes, whose lycopene isomeric content is almost all tetra-cis, provide a useful food source for comparing cis- and trans-isomer absorption. In a study reported by researchers from the Processed Foods Research Unit, Western Regional Research Center, USDA, and the Western Human Nutrition Research Center (also USDA), tangerine tomatoes were processed into sauce in the Univ. of California, Davis pilot plant for subsequent use in a human feeding study. This paper does not report on the feeding studies, but describes the analysis done to determine the amount of the different types of lycopene, and how these different forms survived processing. Samples were taken at several stages during processing; carotenoids were extracted and analyzed for carotenoid-isomer profiles and concentrations. Analyses showed that total lycopene concentration decreased considerably during the 1st step of processing, which included heating and juicing operations. Processing resulted in a large decrease in tetra-cis lycopene concentration accompanied by increases in trans- and other cis-lycopene isomers.

Some interesting techniques were used to process the tomatoes, including a microwave hot-break method used to determine the processing characteristics of various tomato genotypes The Tangerine variety, with a deep orange color, has a high content of 7,7',9,9'-tetra-cis lycopene (80% to 90%). Lycopene is primarily present as the tetra-cis isomer in Tangerine tomatoes. Small amounts of phytoene, phytofluene, carotenes, and smaller amounts of other cis and the all-trans isomer of lycopene are also present. In contrast, raw, as well as cooked, red tomatoes contain primarily the trans-isomer of lycopene. During the 1st steps of processing, which included slicing, heating, cooling, and then juicing, much of thetetra-cis lycopene isomers degraded and a smaller amount of the isomers isomerized to other cis-lycopene isomers. Heating, prolonged exposure to light and oxygen, and juicing are the likely sources of transformation and degradation.

As processing progressed, mostly through heating to concentrate the juice to form sauce, degradation is much less, but isomerization increases. The authors observed an increase in trans-lycopene and a greater increase in other cis isomers of lycopene. Cis-lycopene isomers have been shown to be more bioavailable than the trans isomer, indicating that they are more efficiently absorbed and deliver lycopene into the plasma more effectively. This might be interpreted to mean that cis isomers of lycopene are more beneficial to human health than the trans isomer. p C307-312.

Mushroom Extract as an Antitumor Agent?

A group of scientists from the Pharmaceutical Univ. in China have combined efforts with a group at the Univ. of Maryland to determine whether polysaccharide-based adjuvant for tumor therapy from edible mushrooms including Ganoderma lucidum will prove efficacious. This mushroom, commonly grown in Anhui, China, was compared with a commercial antitumor and imunostimulating agent. The test preparation (GLPP) was characterized for its physicochemical properties, found to have an average molecular weight of 6600 and a specific optical rotation of +25.6°, contained 10.6% protein, and had a molar ratio of 0.9:15:1 for mannose, glucose, and galactose, respectively. The comparison study identified its antitumor and immunostimulation capacity, and potential in reducing the toxic effects induced by cyclophosphamide (Cy) treatment and Cobalt-60 (60Co) radiation in mice. GLPP at levels of 100 and 300 mg/kg body weight (BW)/d significantly inhibited the growth of inoculated S180, Heps, and EAC tumor cells in mice. GLPP at a dose of 300 mg/kg BW/d showed stronger growth inhibition against all 3 tested tumor cells than PSP at 1 g/kg BW/d. GLPP also dose-dependently increased phagocytic index, phagocytic coefficient, and 50% hemolysin value in the EAC tumor-bearing mice, indicating its potential immunostimulating property. In addition, GLPP at 300 mg/kg BW/d was comparable to PSP at 1000 mg/kg BW/d in preventing the decrease of thymus index, spleen index, white blood cells, and bone marrow karyote numbers induced by Cy treatment and 60Co radiation.

The mushroom, known as Ganoderma lucidum (Fr.) Karst is an edible medicinal mushroom, known as “Lingzhi” in China and “Reishi” or “Manetake” in Japan. It has been traditionally used for health promotion and longevity in the China and other East Asian countries for more than 2000 y. A few G. lucidum polysaccharides and polysaccharopeptides, including the commercially available Ganopoly, have been shown to exhibit antitumor and immunostimulating activities. As a major problem with current cancer therapies is the negative effect on the immune system, which continues to effect the lives of cancer survivors for many years after the cancer is no longer active, a compound of this type would be prized by the medical profession and a boon to patients. The present study indicates that the demonstrated antitumor, immunostimulating, leukogenic, and antianemic activities of GLPP in tumorbearing mice suggest the potential utilization of GLPP as an adjuvant to conventional treatments of cancers and its use for cancer prevention. Needless to say, clinical trial would be required to demonstrate efficacy in humans, as well as to learn more about the mechanisms by which this relatively small molecule works. p S435-442.

Some Like it Red

Consumers don't like brownish beef or off-colored pork, turkey, or fish. They believe it suggests that the meat may be bacterially unhealthy, although the color of meat usually begins to change in about 12 d, according to a group of researchers from The Ohio State Univ. Reporting their results of a study of the effectiveness of a spray coating of gelatin on a cut of meat, the coated meat can stay the right color for about as long as the bacterial population remains in check. This would extend shelf-life, benefiting both consumer and producer by eliminating a lot of waste. But the key is applying a spray coating of gelatin. When similar studies were run in past years, dipping and wrapping the meat cut was less efficacious. This study utilized a 20% bovine gelatin solution that was spray-coated onto beef tenderloins, pork loins, salmon fillets, and chicken breasts which were packaged in 80% O2 and 20% CO2 modified atmospheres and stored under fluorescent light at 4 °C for 2 wk. All of the gelatin-coated fresh meat products showed a reduction in purge, the liquid that collects in the bottom of meat trays and enhances the ability of bacteria to thrive. The gelatin reduced purge by acting as a barrier to water loss. There was a reduction in color deterioration for gelatin-coated beef, a slight reduction of color deterioration for gelatin-coated pork, but no reduction in color deterioration for salmon and chicken. The gelatin coat reduced color deterioration by acting as a barrier to oxygen, but also had a negative effect on color due to its own color deterioration. It was found that the gelatin coating didn't reduce lipid oxidation, as it is not an effective barrier for lipid oxidation at refrigerator temperatures.

Sensory analysis of beef tenderloins confirmed that color deterioration was reduced, and flavor was not affected by the application of a gelatin coat. The gelatin coat was equally effective during light and dark storage. It was more effective on vacuum packaged products than on modified atmosphere packaged products. p E382-387.

Understanding the Flavor Niceties of Meal Bars and Shakes

The extreme interest in meal replacement bars and beverages is attested to by the amount of shelf-space in grocery stores to these products. According to the authors from North Carolina State Univ., who studied the organoleptic effects of soy compared to whey proteins in these products, meal replacement products (including bars, liquid, and powdered protein drinks) are projected to reach $8 billion by 2008. Soy and/or whey proteins are commonly added to both meal replacement products (bars and beverages) and bodybuilding products.

Previous work has documented flavors of rehydrated whey and soy proteins. The research team used an experienced, trained descriptive panel to evaluate the flavors of a number of commercial bars, then to evaluate the flavors of prototypes that contained various levels of soy and whey proteins. Flavor and texture lexicons were developed for meal replacement bars and beverages. Commercial peanut butter-flavored meal replacement bars and vanilla meal replacement shakes were evaluated by the panel (n= 9). Prototypes of bars and beverages included 3 levels of whey and soy protein and evaluated.

Sensory properties of prototype bars and beverages fell within the range of commercial products. Prototype bars formulated with whey protein were characterized by sweet aromatic and vanillin flavor notes while the texture was described as adhesive and cohesive. Prototype bars made with soy protein were characterized by nutty flavor while the texture was called tooth-packing and dense. Whey protein contributed to sweet aromatic and vanillin flavors in prototype beverages while soy protein contributed cereal/grainy flavors. Consumer acceptance scores were higher for prototype bars and beverages containing whey protein or a mixture of whey/soy protein than for products made with soy protein alone (P < 0.05). These results will aid researchers and product developers in optimizing sensory quality in meal replacement products. p S425-434.

Soy-Enrichment Requires Flavor and Nutrient Considerations

Nothing is ever easy. As consumer interest in healthy components as well as flavor and texture has increased, more frequent introduction of processed foods containing functional food components is a condition of the market. Researchers from Inha Univ. studied examples of addition of food materials with particular nutrient interests, and found that addition of these food materials can affect the quality of products during processing and storage. In their study of the effect of soy flour when added to dough for frying in corn oil, they found that tocopherols were present in corn oil at 1000 ppm before frying and increased after the first frying of dough containing soy flour due to tocopherol transfer from soy flour-added dough to the oil during frying. However, as the oil was used for repeated frying, tocopherol contents decreased and its degradation rate was higher in the oil that fried soy flour-added dough than in the oil that fried the dough without soy flour.

Soy flour can contribute to the texture and nutrition of the final products because it contains high amounts of tocopherols at 900 to 1200 ppm, phospholipids (PLs) at 0.14 mg%, and isoflavone at 489.1 mg. Although many products added with soy flour have been introduced in the market, there are few studies on the effects of soy flour addition on the products during processing. This study investigated the effects of soy flour addition to flour dough on the oxidation of oil during deep fat frying of the dough. PL and tocopherols in the oil were correlated with the oil oxidation during frying. Increase in the oil oxidation by soy flour added to the dough was highly correlated with fast decomposition of tocopherol in the oil.

So what's a fellow to do when he wants to serve the public by producing fried products with extra soy flour in the formula? Study the frying oil and make sure it's the right one, and check on the quality of soy flour. These researchers did a rather elegant set of experiments to indicate that changing formulas without considering the effects of the formula change on final product can produce results that one really doesn't want. p C317-323.