Industrial Applications of Selected JFS Articles

Throwing away food is preferable to getting food poisoning, but the amount of wasted food is very high— and food supply appears to be getting more critical. So testing for food spoilage organisms, allergens, and chemical problems like heavy metals should be considered very important. Several papers in this issue show the kind of initiative that preserves the food supply, and keeps people eating healthy.

Some Tests Show Peanut Allergen Even When It Isn't There

This paper reminds one of the “man that wasn't there, and wasn't there again today.” When food manufacturers test all ingredients for traces of peanut, they may come a cropper when using ELISA tests for peanut allergens on caramel color. Seems the tests are confused by a matrix interference triggered by some caramel color products, but in final food products, the tests don't show false positives. The paper titled “False Positive Detection of Peanut Residue in Liquid Caramel Coloring Using Commercial ELISA Kits” outlines the Univ. of Nebraska's search for a way to test ingredients without throwing them all away. T1091–T1093

Fruit Wines from Ecuador Offer Nutrition Possibilities

In “Color, Phenolics, and Antioxidant Activity of Blackberry (Rubus glaucus Benth), Blueberry (Vaccinium floribundum Kunth), and Apple Wines from Ecuador”, researchers from universities in Ecuador and Spain studied Ecuadorian local wines to compare the antioxidant characteristics to wine made from red grapes. Blackberry wines compared well to red grape wines, offering higher levels of antioxidants, especially anthocyanins and ellagitannins, and suggesting the possibility of combining blackberry fruit with apples. C985–C993

Fish on Ice

Freshwater farmed tilapia has become very popular with consumers. The mild, bony fish is grown heavily in China, Indonesia, Egypt, and the Philippines. According to the paper “Quality Properties, Fatty Acids, and Biogenic Amines Profile of Fresh Tilapia Stored in Ice”, reasons for its popularity with producers include its rapid growth, resistance to various diseases and stress, tolerance to changing environmental conditions, and willingness to spawn in captivity. FAO thinks that 10 to 12 million tons of seafood spoils annually, and spoiled fish, especially if the spoilage is caused by biogenic amines, can be very dangerous to the consumer. Because 73% of the 2.3 million tons of tilapia produced annually is farmed, there is the opportunity for testing the fish before delivery. To determine both baseline quality and shelf life, the scientists looked properties and fatty acids contents of Nile tilapia (Oreochromis niloticus, stored in ice for 21 days). Quality properties consist of thiobarbituic acid (TBA) value, total volatile basic nitrogen (TVB-N), microbiological analysis, and determination of biogenic amines contents. The content of ash, dry weight, fat, and the fatty acid profile were examined to monitor the overall quality of tilapia. The results? “The biogenic amine content fluctuated highly and did not reach the established deterioration levels even after 21 d of storage, and should not be considered as a proper spoilage indicator. The results show that microbiological analysis is the best method from all mentioned in the research to indicate the spoilage level of tilapia during ice storage and that TBA analysis is rather unstable and differs significantly from researcher to researcher. The work showed that the microbiological spoilage is the main deterioration cause in ice-stored tilapia and may occur within 10 days. This means that the inhibition of growth of microbes should be the main factor of prolonging the shelf life of ice stored tilapia.” Tilapia isn't particularly rich in omega-3 fatty acids, though. S1063–S1068

Mercury in Seafood – a Replay

It hasn't been that many years ago – has it? – when swordfish fell off the U.S. menu because of excessive mercury residues. A few years later, and either overfishing slowed down, or the oceans were cleared of some residues, and folks began to enjoy swordfish again. But there has always been a suggestion of a problem, and the benefits of seafood, especially omega-3 fatty acids, were promoted as a balancing act to mercury. Citizens of Oman eat a lot of seafood, including dried shark, which appears to carry a lot of mercury. The researchers state “The specific purpose of our study was to estimate the levels of mercury in commercially important fish and shellfish species in the Omani coastal marine environment,” and their results are published in “Concentration and Exposure Assessment of Mercury in Commercial Fish and Other Seafood Marketed in Oman.” This study emphasizes that, except in a few cases, the mercury level is lower than the limit value for human consumption recommended by various health organizations. The results showed that “vulnerable groups such as young children, pregnant and nursing women, and women of childbearing age should change their fish consumption patterns, and, in particular, reduce the quantity of dried fish consumed to significantly decrease the likelihood of reaching the limit and to diminish exposure to mercury.” T1082–T1090

Stifling Aflatoxin in Undried Corn

Because this crop year looks unsettled, the work by researchers who reported in “Inhibition of Bacterial and Filamentous Fungal Growth in High Moisture, Nonsterile Corn with Intermittent Pumping of Trans-2-Hexenal Vapor” may help to salvage corn that doesn't dry in the field, and can't be accommodated in driers. The research was done on a pilot model, and was performed to determine whether this volatile can prevent the growth of A. flavus and other naturally occurring fungi and bacteria on high moisture (23%) nonsterilized corn. It appears that “the vaporized T2H eliminates naturally occurring fungi, inoculated A. flavus, as well as most bacteria after either (1) one day of pumping at the 30 min per 2 h rate or (2) pumping cycles of 30 min per 12 h period over the initial 72 h of incubation. Results suggest that intermittent pumping of this volatile could prevent most, if not all, microbial growth on stored corn.” The expense issue will require study, but major aflatoxin loss is expensive as well. M1029–M1035

Cutting the Bacterial Load on Tomatoes

Reducing the incidence of foodborne illness attributed to fresh cut vegetables may start with tomatoes, which are charged with 17.1% of all outbreaks. Because tomatoes are a big deal, second only to potatoes in vegetable popularity, a way of reducing the number and severity of outbreaks would be useful. In “Efficacy of Integrated Treatment of UV light and Low-Dose Gamma Irradiation on Inactivation of Escherichia coli O157:H7 and Salmonella enterica on Grape Tomatoes”, researchers report “Reduction of inoculated pathogens in excess of 5 log was achieved on whole grape tomato by combining UV-C (0.6 kJ/m2) with 0.75 kGy gamma irradiation. The cumulative reductions may be sufficient to render a safe product at the retail level. The current FDA regulations prohibit the application of radiation doses in excess of 1 kGy to fresh fruits and vegetables to prevent quality deteriorations. The doses applied in this study are well within the FDA permissible limit.” M1049–M1056

Pasta that is Dried Slowly, Under Low Heat, Produces Higher-Protein Product

The combination of moisture, amino acids, sugars, and heat, at a slightly acid pH, can produce Maillard Reaction products that rob the final pasta of lysine, and produce textures and flavors that are not among the preferred. This apparently occurs while the pasta is drying. In “Furosine as a Pasta Quality Marker: Evaluation by an Innovative and Fast Chromatographic Approach”, searchers from Italy developed protocols that identified the presence of furosine, an amino acid generated after acid hydrolysis of the Amadori compounds. In general, furosine can be used as a reliable marker of thermal and nutritional damage in foods, and it is used by the Italian food department to identify products like cheese that has been mishandled. The system and values determined by the research team should prove invaluable in identifying pasta that has been handled in a way that promotes lysine retention, and good flavor. C994–C999

Rice Preparation for Different Uses

Rice varieties have different contents of amylopectin and amylose, and cooking methods can change the eating properties of the products. Rice starch is easily hydrolyzed by amylases after ingesting and is considered a high glycemic index (GI) food, so finding preparation methods that increased resistant starch and slows the hydrolysis is helpful for diabetic patients. In “Effects of Cooking Methods and Starch Structures on Starch Hydrolysis Rates of Rice”, researchers from Iowa State Univ., including amylose expert Jay-Lin Jane, found that first steaming, then refrigerating rice, followed by stir-frying, provided the least hydrolysis and the most resistant starch. Cold storage likely provided retrograded starch that did not hydrolyze even after stir frying. If consumers want to keep post-meal sugar spikes level, stir-fried rice seems the way to go. Possibly, food processors might look at inserting a chilling step to increase the amount of retrograded rice starch, making rice dishes that would be good for diabetics. H1076–H1081

Mushroom Waste Produces Probiotics

In “The Applications of Polysaccharides from Various Mushroom Wastes as Prebiotics in Different Systems”, researchers reported that extracted polysaccarides from the leftover parts of mushrooms can be used as prebiotics, to grow lactic acid bacteria for use as probiotics. The researchers identified a symbiotic interaction that occurred between the microbial bacteria and the polysaccharides from different mushroom wastes, altering the balance of the probiotics in the mushroom medium and in a test fermented milk. These mushroom polysaccharides retarded the death of the probiotics, allowing them to maintain higher populations during cold storage. The tolerance and stabilities of the probiotics in simulated gastric juice and bile acid also were improved significantly when they were supplemented with mushroom polysaccharides. The results showed that polysaccharides extracted from inexpensive mushroom wastes have significant potential for use as prebiotics. M1041–M1048