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The more we know about the components of food and the interactions of those components, the better chance industry has of controlling food disease, improving human health, and producing better tasting products. For many years, scientists have labored at fitting the “edge pieces” of this jigsaw puzzle, hoping it fit the pieces all together. The puzzle has reached gigantic proportions, as new food sources continue to develop. But the bigger the puzzle, the more the picture extends and clarifies.

Using and Upgrading Commercially Underused Varieties of Fish

  1. Top of page
  2. Using and Upgrading Commercially Underused Varieties of Fish
  3. Effectiveness of Nylon 6 as a Packaging Material
  4. Improving Shelf Life of Ground Beef
  5. New Methods Help Determine How Small the Sugar
  6. Differences in Meat Components Studied
  7. Lactic Acid Bacteria Serve as Source for Low Calorie Sugars
  8. Better Identification of Dread Oyster Disease

Croaker, a fish that is about the size of a redfish and often smaller (9-in is the lower limit for catching in the U.S.), is found abundantly in the West Sea of Korea. It makes a sound that is a guttural croak, hence the name, and it is not particularly prized as a food source. However, as preferred fish become less available, croaker may find a place in the diet. In Korea, it is usually used as lowgrade surimi or as a binder for fried seafood cakes. As is the case with fish waste or underutilized species, croaker may be used as a nutritional ingredient, especially if treated with protease enzyme to alter the functional properties of the proteins. The authors of this paper, “Enzymatic Hydrolysis of Recovered Protein from Frozen Small Croaker and Functional Properties of Its Hydrolysates”, wanted to recover fish protein isolates from frozen small croaker, to fractionate soluble and insoluble hydrolysates after the process of enzymatic hydrolysis by commercial proteases, and to evaluate functionalities for soluble and insoluble fractions. Functionalities of hydrolysates were also compared with those of known protein additives.

Croaker hydrolysates had different attributes when prepared using different proteases and when the hydrolysis is peformed at different times and temperatures. Extended hydrolysis appears to provide a highly soluble protein, while limited hydrolysis can produce varying types of solubility and binding characteristics. When compared with nonmuscle protein additives, such as egg white, soy protein, and whey proteins, the precipitate from enzyme-treated hydrolysates from underutilized small croaker may find use as functional ingredients of various types. C17-24

Effectiveness of Nylon 6 as a Packaging Material

  1. Top of page
  2. Using and Upgrading Commercially Underused Varieties of Fish
  3. Effectiveness of Nylon 6 as a Packaging Material
  4. Improving Shelf Life of Ground Beef
  5. New Methods Help Determine How Small the Sugar
  6. Differences in Meat Components Studied
  7. Lactic Acid Bacteria Serve as Source for Low Calorie Sugars
  8. Better Identification of Dread Oyster Disease

The paper titled “Effect of Pasteurization, High-Pressure Processing, and Retorting on the Barrier Properties of Nylon 6, Nylon 6/ethylene Vinyl Alcohol, and Nylon 6/nanocomposites Films” reports extensive work done by scientists from Ohio State Univ. and Pliant Films, studying optimal films for use in holding pasteurized and high-pressure-processed foods. Nylon 6 provides a relatively high barrier to gases, odors, and flavors, and possesses good thermal and mechanical properties. Its resistance to flex-cracking and puncture also contributes to the use of nylon 6 in flexible packaging. Nylon 6 is commonly used to package cheeses, fresh and processed meats, frozen foods, and sausages. By combining Nylon 6 with other films including nanoparticles, it is hoped that resulting films might be useful in foods that are pasteurized or high pressure treated for greater food safety.

Various studies have reported on how nanoparticles incorporated into polymers acted to increase the mechanical, barrier, and physical properties of the materials. When used to increase the gas barrier of a polymer, the nanoparticles accomplish this by creating a tortuous path for diffusing gases that pass through the material's matrix. This improvement is advantageous to the food packaging industry only if the nano material maintains its other desirable properties after being exposed to given processing conditions. This study tested this postulation by exposing the test nylons to pasteurization, high-pressure processing (HPP), and retorting conditions.

Pasteurization decreased the barrier properties of N6, N6/EVOH, and N6/Nano, except for the oxygen barrier property of N6/EVOH. On the other hand, HPP did not significantly affect the barrier properties of the materials. Although N6/EVOH had the best resistance toward pasteurization and HPP, it was not able to withstand the retorting conditions. PP-coextruded N6/Nano was best used for the retort process. The N6/nano appeared to have the best barrier to moisture loss after pasteurization, retorting, and HPP exposure. Changes in morphology of the nylon 6 and polypropylene may have influenced the barrier properties of the treated samples. N9-15

Improving Shelf Life of Ground Beef

  1. Top of page
  2. Using and Upgrading Commercially Underused Varieties of Fish
  3. Effectiveness of Nylon 6 as a Packaging Material
  4. Improving Shelf Life of Ground Beef
  5. New Methods Help Determine How Small the Sugar
  6. Differences in Meat Components Studied
  7. Lactic Acid Bacteria Serve as Source for Low Calorie Sugars
  8. Better Identification of Dread Oyster Disease

Antioxidants, properly selected and applied, improve shelf life of ground beef. The paper “Effect of Antioxidant Application Methods on the Color, Lipid Oxidation and Volatiles of Irradiated Ground Beef” reports the effects of 4 antioxidant treatments, either mixed into ground beef, or sprayed on. Because ground beef is the major cut of beef sold in supermarkets, and because a nice red beef color is the single biggest purchasing driver (especially when bright light in the meat case accelerates the browning characteristic of ground beef), finding a good method of increasing case life by a few days is particularly important. Irradiation has grown in popularity as the number of tainted beef recalls has skyrocketed, but is known to speed color change, making ground beef look “older.”

The treatments, selected by researchers from Iowa State Univ. and Konkuk Univ. (Seoul, Korea) were intended to improve color, slow lipid oxidation, retain volatiles, and control carbon monoxide production. The 4 treatments (no additions; 0.05% ascorbic acid; 0.01%α-tocopherol + 0.01% sesamol; and 0.05% ascorbic acid + 0.01%α-tocopherol + 0.01% sesamol) were applied to ground beef using either mixing or spraying method. The meat samples were placed on Styrofoam trays, irradiated at 0 or 2.5 kGy, and then stored for 7 d at 4 °C. Color, lipid oxidation, volatiles, oxidation-reduction potential (ORP), and carbon monoxide (CO) production were determined at 0, 3, and 7 d of storage. Irradiation increased lipid oxidation of ground beef with control and ascorbic acid treatments after 3 d of storage. α-Tocopherol + sesamol and ascorbic acid +α-tocopherol + sesamol treatments were effective in slowing lipid oxidation in ground beef during storage regardless of application methods, but mixing was better than spraying. C25-32

New Methods Help Determine How Small the Sugar

  1. Top of page
  2. Using and Upgrading Commercially Underused Varieties of Fish
  3. Effectiveness of Nylon 6 as a Packaging Material
  4. Improving Shelf Life of Ground Beef
  5. New Methods Help Determine How Small the Sugar
  6. Differences in Meat Components Studied
  7. Lactic Acid Bacteria Serve as Source for Low Calorie Sugars
  8. Better Identification of Dread Oyster Disease

There have been lawsuits and arguments about how the dextrose equivalent of a maltodextrin is measured. For a sugar so small, the controversy has gone on and on. The molecular weight and sugar distribution of specific degrees of polymerization describe the utility of maltodextrins. Researchers from Ferminich Co., a major user of maltodextrins in formulated flavors, have reported some new wrinkles in describing these little functional sugars, and report their findings in “Determination of Dextrose Equivalent Value and Number Average Molecular Weight of Maltodextrin by Osmometry.”

Dextrose equivalent (DE) value is the most common parameter used to characterize the molecular weight of maltodextrins. Its theoretical value is inversely proportional to number average molecular weight, which allows a theoretical basis for correlating a specific product with physical properties that are important to food manufacturing, such as hygroscopicity, glass transition temperature, and colligative properties. The use of freezing point osmometry to measure DE and molecular weight distribution was assessed. Measurements were made on a homologous series of malto-oligomers as well as a variety of commercially available maltodextrin products with DE values ranging from 5 to 18. Results on malto-oligomer samples confirmed that freezing point osmometry provided a linear response with number average molecular weight. Sodium and chloride species in some commercial maltodextrin products were found to be concentrated enough to interfere with DE measurement.

Previous methods of measurement depended on titrations based on copper reduction. They are imprecise and time-consuming, but form parts of the methods that can be used to describe the distribution of different saccharides in a given maltodextrin. Osmometry makes it possible to measure the theoretical Mn and DE of maltodextrins accurately. Osmometric DE determination has been shown to be a rapid, inexpensive, and environmental-friendly method using easy-to-operate, robust, and user-independent instrumentation. C33-40

Differences in Meat Components Studied

  1. Top of page
  2. Using and Upgrading Commercially Underused Varieties of Fish
  3. Effectiveness of Nylon 6 as a Packaging Material
  4. Improving Shelf Life of Ground Beef
  5. New Methods Help Determine How Small the Sugar
  6. Differences in Meat Components Studied
  7. Lactic Acid Bacteria Serve as Source for Low Calorie Sugars
  8. Better Identification of Dread Oyster Disease

In the paper titled “Factors in Various Fractions of Meat Homogenates that Affect the Oxidative Stability of Raw Chicken Breast and Beef Loin”, researchers from Iowa State Univ. and USDA analyzed the various components of chicken breast and beef loin to determine why beef loin flavor is less stable to oxidation than is chicken breast. As model systems, these 2 cuts of meat include various antioxidant and prooxidant factors. The researchers studied meat homogenate, precipitate, and supernatant of homogenate after centrifugation, and high and low molecular weight fractions from the supernatant. Chicken breast showed greater oxidative stability than beef loin during 10-d storage. All fractions that were derived from chicken breast showed lower amounts of free ionic iron and myoglobin and higher total antioxidant capacity than those from beef loin during storage.

The oxidative stability of chicken breast was ascribed to high, stable total antioxidant capacity with low level of catalysts for lipid oxidation. The water-soluble high molecular weight fraction, which contained myoglobin, was responsible for the high lipoxygenase-like activity and lipid oxidation potential (LOP) in beef loin. The total antioxidant capacity of all of the fractions from beef loin decreased over storage, suggesting that high myoglobin content upset the balance between pro- and antioxidant factors in the beef loin, and contained catalysts such as ferrylmyoglobin, hematin, and/or free ionic iron that triggered the lipid oxidation in beef loin. Beef, a major source of dietary iron contents, carries with its dietary advantages, flavor disadvantages. C41-48

Lactic Acid Bacteria Serve as Source for Low Calorie Sugars

  1. Top of page
  2. Using and Upgrading Commercially Underused Varieties of Fish
  3. Effectiveness of Nylon 6 as a Packaging Material
  4. Improving Shelf Life of Ground Beef
  5. New Methods Help Determine How Small the Sugar
  6. Differences in Meat Components Studied
  7. Lactic Acid Bacteria Serve as Source for Low Calorie Sugars
  8. Better Identification of Dread Oyster Disease

Lactic acid bacteria serve as a primordial stew, producing the basis for a number of low-calorie sweeteners that depend on their specific “shape” for their reduced digestibility and physiological affect. “Technological and Functional Applications of Low-Calorie Sweeteners from Lactic Acid Bacteria” describes the production of these sweeteners and their health benefits such as low calories, low glycemic index, anticariogenic, osmotic diuretics, obesity control, probiotic and technological attributes (sugar replacer, bulking agent, texturizer, humectant, cryoprotectant). Some of these sweeteners successfully produced by lactic acid bacteria include mannitol, sorbitol, tagatose, and trehalose and there is a potential to increase their variety and numbers using metabolic engineering. The paper serves as an update on varieties of new sugars, as well as a valuable bibliography on the subject. R16-23

Better Identification of Dread Oyster Disease

  1. Top of page
  2. Using and Upgrading Commercially Underused Varieties of Fish
  3. Effectiveness of Nylon 6 as a Packaging Material
  4. Improving Shelf Life of Ground Beef
  5. New Methods Help Determine How Small the Sugar
  6. Differences in Meat Components Studied
  7. Lactic Acid Bacteria Serve as Source for Low Calorie Sugars
  8. Better Identification of Dread Oyster Disease

Vibrio vulnificans is responsible for about 95% of the cases of death by oyster—and the disease is ubiquitous when water over oyster beds is warm. Researchers from Louisiana State Univ. reported their successful search for a direct method of testing for this scourge of oyster-lovers in “Detection and Enumeration of Vibrio vulnificus by Direct Colony Immunoblot.” The DCI detected all clinical and environmental V. vulnificus strains tested and did not cross-react with other Vibrio species including V. cholerae, V. parahaemolyticus, or V. fluvialis. The DCI was then compared to the DNA hybridization procedure (DNAH) using V. vulnificus agar plates inoculated with mixed cultures of V. vulnificus and V. parahaemolyticus and V. vulnificus-seeded oyster homogenates. Both DCI and DNAH detected 1 to 2 log colony forming units/mL V. vulnificus mixed with 4 log CFU/mL V. parahaemolyticus. Both methods were comparable and demonstrated no significant statistical differences when enumerating V. vulnificus in mixed cultures or in oyster homogenates seeded with levels of V. vulnificus from 2 to 6 log CFU/mL. The DCI demonstrated clearer color development and was less time-consuming than the DNAH. The fast, accurate test could identify oysters contaminated with small but deadly amounts of the bacteria, allowing better control of the pathogen. M41-45