SEARCH

SEARCH BY CITATION

Keeping flavor on the preferred side of the food scale while protecting food safety and health remains important to the consuming public. When consumers fail to trust the safety of food in restaurants and the grocery store, they still eat, but they make noise about bigger and meaner regulations that often won't help. But additional regulations can add a bundle to the weekly grocery cart—and that upsets the consumer at least as much. Avoiding bacterial contamination, keeping salt content to a minimum for a susceptible public, and retaining both flavor and active phytochemical ingredients are all desired ends to food science. Here are some ideas:

Salt/Vinegar Interactions May Allow Reduction in Salty Foods

  1. Top of page
  2. Salt/Vinegar Interactions May Allow Reduction in Salty Foods
  3. Storage Conditions Studied for Blueberries
  4. A Better Way to Avoid Salmonella on Alfalfa Sprouts
  5. Measuring the Quality of Sour
  6. Knowing Your Onions
  7. Open Sesame—Better Roasting Improves Oil and Flour
  8. Raisin' the Bar for Bread Ingredients
  9. Improving Shelf Life of Pure Gold

The action of governmental groups to recommend salt reduction in more than half of the American population follows the activity of other countries in asking food manufacturers and restauranteurs to reduce salt in commonly consumed foods. A group of Japanese scientists studied the interacation between levels of salt and vinegar, finding that at some levels salt flavor is enhanced by food acids such as vinegar, possibly permitting reduction in salt in certain foods. They report their results in the paper titled “Saltiness and Acidity: Detection and Recognition Thresholds and Their Interaction Near the Threshold”. According to the researchers, it is common practice to add some acid to a food in order to enhance its saltiness when the salt concentration is low.

The research team studied threshold levels for salt and 2 commonly-used vinegars. Then each ingredient was presented at half of the threshold concentration. The net result, according to the paper: “When vinegar at a half concentration of the detection threshold of each panelist was added to the salt solution, both the detection and recognition thresholds of salt were reduced significantly to the level of 3σ. This result strongly endorses the usual practice to substitute part of salt with vinegar to give a satisfactory salty taste in dishes. This phenomenon is more pronounced with rice black vinegar than with rice vinegar.” Despite the conventional wisdom, it doesn't appear to work the other way round. S147-153

Storage Conditions Studied for Blueberries

  1. Top of page
  2. Salt/Vinegar Interactions May Allow Reduction in Salty Foods
  3. Storage Conditions Studied for Blueberries
  4. A Better Way to Avoid Salmonella on Alfalfa Sprouts
  5. Measuring the Quality of Sour
  6. Knowing Your Onions
  7. Open Sesame—Better Roasting Improves Oil and Flour
  8. Raisin' the Bar for Bread Ingredients
  9. Improving Shelf Life of Pure Gold

Argentina is a major producer of blueberries for export to the North American market. For those of us who like fresh blueberries year-round, better understanding of the components of controlled atmospheric storage can make a big difference in how good those midwinter berries are and how much they cost. The paper “Quality Changes of Highbush Blueberries Fruit Stored in CA with Different CO2 Levels” describes the work of a group of researchers from Argentina in improving the quality of this fruit which is now a popular component of high antioxidant foods as well as a corn-flake topper.

Describing the protocols used, the group evaluated quality changes in blueberries during CA storage at (0 °C) with different concentrations of CO2 (5%, 10%, and 15%) combined with 5%O2, respectively. Atmospheric air (20.9% O2+ 0.03% CO2) was used as control. From samples taken at 0, 24, and 48 d of storage, unmarketable fruits and weight loss were recorded as well as color (h), firmness (g), soluble solid content (%), titratable acidity (% citric acid), ratio and the monomeric anthocyanin content (ppm). At each sampling time, additional units were kept for 3 d at 10 °C to simulate retail holding conditions. Irrespective of gas concentration, 0.9% of the initial fresh weight was lost after 48 d at 0 °C. CA fruit had better quality than control at the 24 d sampling, but due to the high number of unmarketable fruits, this advantage was not observed at 48 d at 0 °C. After 24 d of storage, fruits for CA treatments were more firm and had better color, with higher anthocyanin and acidity levels. Soluble solid content showed no significant differences throughout the cold storage period. Residual effect of CA storage was observed at the retail holding condition yielding better firmness, acidity, and ratio. So, for 24 d, CA treatments kept the fruit in better shape. But 48 d is a stretch—all treatments of fruit yielded problems with soft fruit and blemishes. The exercise was to select the best mixtures of gases, and to determine how long the blueberries could be in transit. It appears that controlled atmospheric holding may extend shelf life somewhat. But not, it seems, for a month and a half. S154-159

A Better Way to Avoid Salmonella on Alfalfa Sprouts

  1. Top of page
  2. Salt/Vinegar Interactions May Allow Reduction in Salty Foods
  3. Storage Conditions Studied for Blueberries
  4. A Better Way to Avoid Salmonella on Alfalfa Sprouts
  5. Measuring the Quality of Sour
  6. Knowing Your Onions
  7. Open Sesame—Better Roasting Improves Oil and Flour
  8. Raisin' the Bar for Bread Ingredients
  9. Improving Shelf Life of Pure Gold

Chlorine (as calcium hypochlorite) has been used for decontaminating alfalfa seeds for use in growing sprouts since the mid-1990s, after studies of several disinfectants proved somewhat effective. But it is also effectively forming other compounds that are less-than-safe, and a number of reports have shown that chlorine, when making contact with organic matter, can rapidly form carcinogenic byproducts. In addition, the antimicrobial efficiency of chlorine is greatly affected by pH of the treatment solution and can be rapidly diminished by making contact with organic matters. Because of the drawbacks associated with the use of chlorine, it is desirable to identify a safer and more effective sanitizer for disinfection of alfalfa seeds destined for sprout production. USDA researchers studied acidified sodium chlorite and reported the results in “Acidified Sodium Chlorite as an Alternative to Chlorine for Elimination of Salmonella on Alfalfa Seeds”. When the treatment is adjusted for time, the ACS causes fewer additional compounds and improves germination of the seed, as well as providing safe sprouts. M159-164

Measuring the Quality of Sour

  1. Top of page
  2. Salt/Vinegar Interactions May Allow Reduction in Salty Foods
  3. Storage Conditions Studied for Blueberries
  4. A Better Way to Avoid Salmonella on Alfalfa Sprouts
  5. Measuring the Quality of Sour
  6. Knowing Your Onions
  7. Open Sesame—Better Roasting Improves Oil and Flour
  8. Raisin' the Bar for Bread Ingredients
  9. Improving Shelf Life of Pure Gold

Organic anions and sodium ions are believed to suppress sour taste by means of physiological interactions at the cellular/epithelial level or by cognitive interactions occurring at the central processing level. But the suppression of sour taste appears to be governed by the amount of sodium ions added in the form of NaOH. Addition of small amounts of salt to acid solutions in the absence of anions, at constant pH, and with protonated organic acid species results in a significant decrease in sour taste intensity. Sour taste intensity was unaffected by higher concentrations of NaCl, although these solutions had a significant increase in salty taste. Researchers from USDA and North Carolina State Univ. studied these interactions, and report their results in “Effects of pH Adjustment and Sodium Ions on Sour Taste Intensity of Organic Acids”. S165-169

Knowing Your Onions

  1. Top of page
  2. Salt/Vinegar Interactions May Allow Reduction in Salty Foods
  3. Storage Conditions Studied for Blueberries
  4. A Better Way to Avoid Salmonella on Alfalfa Sprouts
  5. Measuring the Quality of Sour
  6. Knowing Your Onions
  7. Open Sesame—Better Roasting Improves Oil and Flour
  8. Raisin' the Bar for Bread Ingredients
  9. Improving Shelf Life of Pure Gold

Onions are rich in a variety of compounds, including sulfur compounds and sugars. The range of these compounds is further complicated by heat treatments. A group of researchers from France and Belgium studied the movement of compounds from fried and raw onion dices, publishing their findings as “Comparison of Mono- and Di-Saccharides Release in Aqueous Solutions by Raw or Fried Dice of Onion (Allium Cepa L.) Bulbs using Quantitative Nuclear Magnetic Resonance (qNMR)”. First, they soaked the diced onions for 11 d and measured the main sugars: a mix of fructose, dextrose, and sucrose. They found that these and other compounds were released from channels (mainly conductive tissues). They found that most of the sugars were released within 48 h of beginning the soaking process. While frying the onions produced no measurable water-soluble compounds, the extraction kinetics were different. The onion bulb is a storage organ, and nonstructural carbohydrates account for a major portion (64 to 80% by weight) of their dry matter. Most studies agree that the main nonstructural soluble carbohydrates are free glucose, free fructose, sucrose, and a series of fructooligosaccharides, that is, fructosyl polymers with degrees of polymerization up to 12. The reducing sugars (glucose and fructose) contents of 12 varieties of onion was determined to range from 12 to 22 g/100 g of dry weight, while nonreducing sugars varied between 25 to 62 g/100 g of dry weight. Because onions are used in many dishes for flavor, the researchers wanted to study which flavor compounds were released before the dish was consumed. The combination of fat, heat, and sugar produces complex flavors that need to be better understood. C319-325

Open Sesame—Better Roasting Improves Oil and Flour

  1. Top of page
  2. Salt/Vinegar Interactions May Allow Reduction in Salty Foods
  3. Storage Conditions Studied for Blueberries
  4. A Better Way to Avoid Salmonella on Alfalfa Sprouts
  5. Measuring the Quality of Sour
  6. Knowing Your Onions
  7. Open Sesame—Better Roasting Improves Oil and Flour
  8. Raisin' the Bar for Bread Ingredients
  9. Improving Shelf Life of Pure Gold

Infrared heating of sesame seed provides improved oil and flour on extraction, primarily because of the improved efficiency in converting the lignan component sesamolin to sesamol, increasing the production of tocopherols and improving oxidative stability. Researchers from the Central Food Technology Inst. of India studied the conversion and reported their results in the paper titled “Effect of Infrared Heating on the Formation of Sesamol and Quality of Defatted Flours from Sesamum indicum L.”. Not only were resulting oils improved for oxidative stability, but so were the defatted flours. There were no significant differences in the tocopherol content and oxidative stability of the oil. Methionine and cysteine content of the flours remained unchanged due to roasting. The functional properties of defatted flours obtained from either IR roasted or conventionally roasted sesame seeds remained the same. Sesame oil is more stable to oxidation than other vegetable oils, a quality attributed to the presence of tocopherols and the formation of sesamol, the thermal degradation product of sesamolin—a lignan present in sesame. Roasting of sesame seeds before oil extraction increases sesamol (a more potent antioxidant than the parent molecule) content, producing an oil that requires no winterizing. The conversion efficiency of sesamolin to sesamol is increased by 31% by infrared roasting of seeds compared to electric drum roasting. This can be used industrially to obtain roasted oil with greater oxidative stability. H105-111

Raisin' the Bar for Bread Ingredients

  1. Top of page
  2. Salt/Vinegar Interactions May Allow Reduction in Salty Foods
  3. Storage Conditions Studied for Blueberries
  4. A Better Way to Avoid Salmonella on Alfalfa Sprouts
  5. Measuring the Quality of Sour
  6. Knowing Your Onions
  7. Open Sesame—Better Roasting Improves Oil and Flour
  8. Raisin' the Bar for Bread Ingredients
  9. Improving Shelf Life of Pure Gold

In “Application of Raisin Extracts as Preservatives in Liquid Bread and Bread Systems”, researchers from North Dakota State and Embassy Flavors, a Canadian ingredient company, studied the effect of raisin-based ingredients on populations of B. licheniformis and B. subtilis, as well as Aspergillus flavus and Penicillium chrysogenum. Liquid raisin concentrate (RJC) and raisin paste were tested for antifungal activity in liquid bread model system and bread. In the liquid bread model, concentrations as low as 20 and 36 mg crude extract or RJC per gram media significantly (P < 0.05) reduced the populations of the molds at 80 and 470 mg crude extract per gram media, respectively. Bread formulas containing 7.5% of a water extract (equivalent to 70mg extract per gram dough) or RJC (70mg/g dough) produced bread that had equivalent mold-free shelf life. The mean mold-free shelf life of the bread containing 7.5% water extract was 18.1 ± 3.3 d at room temperature while the negative control was mold free for 9.4 ± 2.4 d. The antifungal efficacy of the extracts in bread was equivalent to 0.24% calcium propionate in 21 d of storage. Doubling the concentration of the extract did not improve the mold-retarding property in bread. The bread containing raisin paste, the percentage of which in dough was equivalent to 15% raisin extract, exhibited a stronger antifungal activity than did the extracts in bread.

Why does it work? Raisins contain high levels of the natural preservative propionic acid and have been shown to have antimicrobial activities. Raisin syrup or raisin juice concentrate contains 500 to 600 mg/kg of propionic acid (Cantor 1996), and is used as a natural preservative in breads. Raisins allow the baker to reduce or eliminate the use of synthetic preservatives and extend the shelf life of products in a natural way. Besides propionic acid, phenolic compounds and Maillard reaction products (MRP) in raisins may also contribute to raisin antimicrobial activity. M177-184

Improving Shelf Life of Pure Gold

  1. Top of page
  2. Salt/Vinegar Interactions May Allow Reduction in Salty Foods
  3. Storage Conditions Studied for Blueberries
  4. A Better Way to Avoid Salmonella on Alfalfa Sprouts
  5. Measuring the Quality of Sour
  6. Knowing Your Onions
  7. Open Sesame—Better Roasting Improves Oil and Flour
  8. Raisin' the Bar for Bread Ingredients
  9. Improving Shelf Life of Pure Gold

… Or at least a product worth about as much. Black truffles are highly prized and extremely expensive. They also last only a few days, and carry lots of different bacteria along the way. In “Irradiation Treatments to Improve the Shelf Life of Fresh Black Truffles (Truffles Preservation by Gamma-Rays)”, a group of Italian researchers expound on the possibility of making the wild truffle a little more domestic in its habits, losing at least part of the bacterial miasma that comes with the expensive little treasure. Gamma radiation appears to help the situation, and preserve flavor and texture better than other methods have done. M196-200