Industrial Application Briefs

As we learn more and more about the structure of both complex foods and more simple ones, food scientists are able to improve healing properties, flavors, and shelf life. Knowledge of structure also provides information about food safety, processing parameters.

Take 2 Aspirin and an ALA Dose and Call Me in the Morning

α-Lipoic acid (ALA) is an “important vitamin in all eukaryotic and prokaryotic cells where it plays an important role in different metabolic pathways. It is present inside cells in 2 different forms, oxidized and reduced (dihydrolipoic acid, DHLA). ALA has got an antioxidant action, because it can bind directly, or indirectly, to free radicals and it is able to interact with other antioxidants.” ALA is a usual ingredient in nutrient mixtures aimed at the overactive, and to fight aging. How does it do this? In “Alpha-Lipoic Acid Protects against Indomethacin-Induced Gastric Oxidative Toxicity by Modulating Antioxidant System”, a group of Turkish scientists evaluated reports that ALA can prevent certain pathologies in which reactive oxygen species (ROS) have been implicated, such as ischemia-reperfusion injury, sepsis, diabetes, inflammation, neurodegeneration, hypertension, radiation injury, and HIV activation. The researchers found ALA also increased the level of glutathione (GSH) and activities of superoxide dismutase (SOD) and glutathione S-transferase (GST) that were decreased in gastric damaged stomach tissues. In conclusion, the gastroprotective effect of ALA could be attributed to its ameliorating effect on the antioxidant defense systems. And ALA appears to have curative effects on gastric tissues that are irritated by the ubiquitous non-steroidal pain pills that just about everyone pops when muscles ache. H224–H230

Sweet Potato Protein from Peels Helpful in Treating Illnesses

Proteins extracted from sweet potato peels appear to have antidiabetic, antioxidant, and antiproliferative characteristics. A group of North Carolina State scientists reported their research in “Chemical Optimization of Protein Extraction from Sweet Potato (Ipomoea batatas) Peel”. Extraction is probably easier when used on post-blanch peel, and blending, mixed blanched and unblanched peels plus NaCl and precipitation yielded significant amounts of protein, at a relatively low cost. By using the optimized conditions demonstrated in the paper, protein can be isolated and used for products intended for Type II diabetics – of which there is an exploding number. According to the researchers, “Using the optimum conditions, 32.0% of the protein present in blanched peel was recovered in the extract, which consisted of 41.3% protein. Gel electrophoresis and glycoprotein staining suggests that the antidiabetic proteins in Caiapo Potato powder, an extract of a white-skinned sweet potato cultivar, may also be present in extracts from orange-fleshed sweet potatoes.”E307–E312

Grains without Gluten Are Characterized for Better Understanding

Grains such as quinoa and emmer were characterized alongside durum wheat for antioxidant activity and different antioxidant mechanisms. Quinoa grows naturally in the Andes – and has gained a certain amount of commercial activity as a replacement for wheat and durum wheat as the number of patients with celiac disease has increased. The LOX/RNO and ORAC methods measured in quinoa flour a remarkable AAH+L+FSP higher than durum wheat, although lower than emmer; according to the same assays, the IBP component of quinoa resulted less active than in the durum wheat and emmer. In “Antioxidant Activity of Free and Bound Compounds in Quinoa (Chenopodium quinoa Willd.) Seeds in Comparison with Durum Wheat and Emmer”, researchers note that “the results of this study highlight an excellent antioxidant potential of quinoa seeds. This strongly encourages the use of quinoa for improving nutritive and health-beneficial properties of gluten-free food products, targeted not only for celiac patients, but also for the general population.”C1150–C1155

Exotic Oil Mixtures Have Pluses, Minuses

In parts of Asia, perilla oil is used as an edible oil that is valued more for its medicinal benefit than for its flavor. Perilla oil is a very rich source of the omega-3 fatty acid alpha-linolenic acid (ALA). About 50 to 60% of the oil consists of ALA. By combining perilla oil with extra-virgin olive oil, a blend is provided that was investigated for special qualities. The results are included in the paper “Singlet Oxygen-Related Photooxidative Stability and Antioxidant Changes of Diacylglycerol-Rich Oil Derived from Mixture of Olive and Perilla Oil”. Singlet oxygen-related photooxidation was higher and faster in diacylglycerol (DAG)-rich oil derived from triacylglycerol (TAG) oil of extra virgin olive and perilla oil (6:4, w/w) mixture than in its respective TAG oil. Difference in light intensity between 1700 and 2500 lux did not exert a significantly different effect on the oxidation of DAG-rich oil. Compositions of fatty acids and lipid subclasses of DAG-rich oil did not change significantly during the photooxidation. Tocopherols rather than polyphenols were effective antioxidants in the singlet oxygen-related phootooxidation of DAG-rich oil. While DAG oil containing high amount of oleic and linolenic acids can help prevent the cardiovascular diseases as well as obesity, its oxidative stability can be a problem for the food industry. Or perhaps we should say, an opportunity!C1185–C1191

Swelling of Dark Chocolate Shells in Filled Chocolates Now Better Understood

In “Chocolate Swelling during Storage Caused by Fat or Moisture Migration” describes the new methods of quantification of changes in a dark chocolate shell during storage. Researchers used a confocal chromatic displacement sensor to scan the height profile of confection pieces several times during storage, and correlated the information with data on moisture and fat migration, showing the difference on swelling behavior kinetics. The researchers found that once a water activity of 0.8 was reached via moisture migration, swelling was rapid. Fat migration produced more pronounced swelling than moisture migration, and the researchers noted that this may be by inducing phase transition in the continuous cocoa butter phase. The filling ingredients are important to the amount of swelling that occurs. Swelling of the chocolate shell triggers softening, cracking, and sugar bloom on the shell. It shortens shelf life of the products, causing loss of revenue, and difficulties in predicting inventory levels. E328–E334

What Does an Apple Taste Like?

What's your favorite apple? Is it a crisp, juicy Granny Smith, or a softer-fleshed Red Delicious? The flavors and their release mechanisms were studied in “In Vitro and In Vivo Flavor Release from Intact and Fresh-Cut Apple in Relation with Genetic, Textural, and Physicochemical Parameters”, where several favorite apples were studied for flavor release characteristics. The several flavor compounds (esters, aldehydes, alcohols, and terpenes) were measured. Fresh-cut samples were richest in acetaldehyde, while cut Golden and Red Delicious apples had a lower intensity for ester related peaks. Static headspace analysis of intact fruits revealed Fuji and Granny Smith apples had the lowest concentration for all measured flavor compounds. This study can be important in delivering the kind of apple flavor that specific consumers want. The researchers concluded that “A mechanistic approach based on the combination of nosespace data with textural, physicochemical, and structural deformation properties for a larger number of cultivar is needed to effectively elucidate the flavor perception during consumption of real food systems.”C1226–C1233

When It Comes to Bran, the Nose Knows

Can the electronic nose discriminate between types of bran in refined or whole wheat bread? According to the data presented in “Discrimination of Volatiles of Refined and Whole Wheat Bread Made from Red and White Wheat Bran Using an Electronic Nose”, it seems that the electronic nose can, indeed, generally discriminate between both crust and crumb of bread made with hard red and white wheat. On those occasions when white bran whole wheat crumb was misclassified, it was classified as refined bread crumb. Crust of the loaves was a more dependable way to identify which loaf was made with whole wheat flour. Why do we care? Consumers prefer bread with the aroma of refined bread, and the aroma can be adjusted by using white bran instead of red in whole wheat loaves. And electronic noses never catch cold!S399–S406

Wild Herb Appears to Have Most Antimicrobial Activities

A wild-growing herb called Echicophora platyloba D.A. has been evaluated as a phytochemical and as an antifungal, and found interesting. In “Chemical Composition and Antioxidative Activity of Echinophora platyloba DC. Essential Oil, and Its Interaction with Natural Antimicrobials against Food-Borne Pathogens and Spoilage Organisms”, the herb was tested as an antimicrobial against Listeria monocytogenes, Bacillus cereus, Bacillus subtilis, Staphylococcus aureus, Salmonella typhimurium, Escherichia coli O157:H7, Pseudomonas aeruginosa, Candida albicans, Candida tropicalis, Rhodotorula rubra, and Rhodotorula mucilaginosa. The G.C. examinations showed some 33 compounds, including other herb-like ingredients, such as carvacol and thymol, and others. The essential oil showed antimicrobial activity against certain food-borne bacteria, including S. aureus and E. coli 0157:H7, and others The herb grows wild in Iran and the surrounding areas, and may serve as a natural antimicrobial in foods. M631–M637

How Much Ice?

No, this isn't about party planning. It's about advance planning for days at sea for fishing fleets, and it's more important than a warm mojito. In “Calculating Quantities of Ice for Cooling and Maintenance of Freshly Harvested Fish at Sea”, a new model is developed for predicting the amount of ice needed to cool an expected day's catch. These predictions are for bluefin tuna, and the catch size is 2000 to 80000 kg at ambient temperatures between 15 and 36 °C. According to the research, 1 kg of ice is needed for each 3.5 kb of southern bluefin tuna. The ice is in a slurry form, consisting of small particles, to avoid damaging the fish flesh. It's stored in insulated boxes, and doesn't have to be made of distilled water. To simulate how much ice is needed, the following measurements are necessary:

  • 1The maximum ambient temperature, or value expected, while at sea, TA
  • 2Mass of fish that is expected in the day's catch mf, the initial uniform temperature of the freshly harvested fish T0, the specific heat of the particular fish species Cf, and the cooling temperature of the thermal center of the fish that has to be met and maintained at sea, TC
  • 3Outer dimensions of the insulated box and the thickness of the polystyrene insulating material and, strictly, whether the boxes are in shaded areas or sunny areas onboard. E335–E341