Sweetness quality

With the general name of cyclohexylsulphamate, this sweetener was discovered in 1937 by Michael Sveda at the University of Illinois. The sodium salt is the most commonly used form. It is a white crystalline salt with good solubility. The relative sweetness of cyclamate is comparatively low, at approximately 35, in most food systems (Bakal, 1983). The taste quality of cyclamate as a sole sweetener has a slow onset time and can have a sweet/sour aftertaste at high concentrations (Franta et al., 1986). Sweetness quality is greatly unproved in combination with other sweeteners. Cyclamate is synergistic with acesulfame K (Von Rymon Lipinsky, 1985), aspartame (Searle, 1971), saccharin (Von Rymon Lipinsky, 1987) and sucralose (Tate Lyle Pic, 2002). 

The sweetness quality of sucralose is similar to that of sucrose. Sucralose exhibits synergism with acesulfame K, cyclamate, saccharin and stevioside (Tate Lyle Pic, 1985a, 1986). It is not synergistic with sucrose and shows little sweetness intensity synergy with aspartame. However, the sweetness quality of sucralose can be improved in cola by blending with aspartame (Tate Lyle Pic, 1985b). 

As mentioned earlier in this chapter, the a-syn-oxime, perillartine (10) is a semisynthetic compound prepared from a natural product, perillaldehyde, isolated fi om Perilla frutescens (L.) Britton (Labiatae). Although it is used commercially in Japan, its poor solubility and poor sweetness qualities have limited its further development [20,28]. 

Sweetness quality and intensity of various glucosyl derivatives of stevioside... 

Four characteristics of odor are subject to measurement by sensory techniques intensity, detectability, character (quality), and hedonic tone (pleasantness-unpleasantness) (16). Odor intensity is the magnitude of the perceived sensation and is classified by a descriptive scale, e.g., faint-moderate-strong, or a 1-10 numerical scale. The detectability of an odor or threshold limit is not an absolute level but depends on how the odorant is present, e.g., alone or in a mixture. Odor character or qualit) is the characteristic which permits its description or classification by comparison to other odors, i.e., sweet or sour, or like that of a skunk. The last characteristic is the hedonic type, which refers to the acceptability of an odorant. For the infrequent visitor, the smell of a large commercial bread bakery may be of high intensity but pleasant. For the nearby resident, the smell may be less acceptable. 

Although I have defined terms such as quality control and quality assurance in this chapter, what is important is not the definition but the deeds which it imbues. Whether we call the set of principles I have listed under the heading Quality assurance, Quality Assurance, Quality Improvement or Quality Control makes no difference since it does not change the set of principles. We often seem to invent a term then decide what it means rather than invent or discover a set of principles and think of a suitable name which conveys exactly what we intend without confusing people. Instead of saying Quality control is. .. or TQM is. .. to which there will be many propositions, we should be asking What should we call this group of principles so that we can communicate with each other more efficiently As Shakespeare once said That which we call a rose/By any other name would smell as sweet. ... 

The circulating catalyst in the FCC unit is called equilibrium catalyst, or simply E-cat. Periodically, quantities of equilibrium catalyst are withdrawn and stored in the E-cat hopper for future disposal. A refinery that processes residue feedstocks can use good-quality F-cat from a refinery that processes light sweet feed. Residue feedstocks contain large quantities of impurities, such as metals and requires high rates of fresh catalyst. The use of a good-quality E-cat in conjunction with fresh catalyst can be cost-effective in maintaining low catahst costs. 

Sake is a subtle drink. It is sometimes described as having umami, or criticized for its lack of umami. Umami, which some characterize as a flavor, like sweetness or sourness, is a quality of palatability and the degree to which something satisfies the palate. A Zen archer s version of hitting the spot. ... 

Sweetness is a quality that defies definition, but whose complexity can be appreciated merely by examining the molecular structures of those compounds that elicit the sensation. They come in all molecular shapes and sizes, and they belong to such seemingly unrelated classes of compounds as aliphatic and aromatic organic compounds, amino acids, peptides and proteins, carbohydrates, complex glycosides, and even certain inorganic salts. 

As with sweetness, an enantiomeric difference in response is observed in the bitter-taste quality. Isodonal (113) and dihydroisodonal (114) are bitter. 

It has been proposed " that the mechanism(s) of action of gymnemic acids and ziziphins is a biphasic, model-membrane penetration-process. The model suggested that the modifier molecules interact first with the receptor-cell plasma-membrane surface. It was postulated that this initial interaction involves a selective effect on taste perception, including the transduction and quality specification of the sweet stimuli, and selective depression of sweetness perception. Following the initial interaction, the modifier molecules interact with the membrane-lipid interior to produce a general disruption of membrane function and a nonselective effect on taste... 

Although some neural fibers respond to sweet-stimulus compounds placed on the tongue, others do not. This pattern of sensitivity is often a very complicated one. The fibers often respond to more than one, sometimes even to all, of the four taste modalities. Very rarely does a fiber respond specifically to only sweet or salty substances. Furthermore, other fibers may have an entirely different spectrum of sensitivities, and may respond strongly to one sweetener and very weakly to another. Pfaffmann reported how two fibers, one having one pattern of sensitivity to taste, and the other, a different pattern, can signal two different taste-qualities, even though... 

Food colorants play an important role in quality perception. Color is often the first notable characteristic of a food and it influences the expectations of consumers buying the product and also influences food handlers who make quality-related decisions, for example, during visual inspections." More specifically, color predetermines our expectations and perceptions of flavor and taste. " Color is interrelated with flavor intensity (detection threshold), with sweetness and salinity sensations, and also with our susceptibilities to and preferences for products. For example, consumers perceived a strongly red-colored strawberry-flavored drink to be sweeter than a less colored version, and yellow was associated with lemon and pink with grapefruit, but by reversing the colors, flavor perception changed." If food color is not appealing, consumers will not enjoy the flavor and texture of the food. ... 

Another new aspect of this concept is that it does not include a single optimum quality. For example, some consumers like green, firm, juicy apples, and others prefer blushed, sweet, aromatic apples. So, there is some freedom to choose a more growth-related or a more differentiation-related optimal balance when managing the crop. 

Multiple senses, including taste, contribute to our total perception of food. Our perception of the flavor of food is a complex experience based upon multiple senses taste per se, which includes sweet, sour, salty and bitter olfaction, which includes aromas touch, also termed mouth feel , that is, texture and fat content and thermoreception and nociception caused by pungent spices and irritants. Taste proper is commonly divided into four categories of primary stimuli sweet, sour, salty and bitter. One other primary taste quality, termed umami (the taste of L-glutamate), is still somewhat controversial. Mixtures of these primaries can mimic the tastes of more complex foods. 

Feeding studies. Although sweet potatoes are a significant source of calories in many parts of the world, very little information is available concerning the nutritional quality of sweet potato protein as determined by controlled feeding studies in humans. 

A report by Bressani et al. (3J7), which evaluated the nutritional value of diets based on starchy foods and beans, indicated that for the rat, sweet potato protein was of poor nutritional quality. When methionine was added to all diets to raise sulfur amino acids, sweet potato still required the largest amount of supplementation with bean flour to maintain animal weight (Table II). 

Sweet potato flour contained 3.8% protein, the second highest amount of protein among starchy foods, and yet the protein appeared to be the poorest in nutritional quality. However, it should be noted that the sweet potatoes used in this study were dried at 60 C but were not cooked. Uncooked sweet potato starch is not completely digestable by rodents. As a consequence, maintenance requirements would increase. This is the most likely explanation for the increased requirement for bean flour, but there also may have been interference with digestion from protease inhibitors present in uncooked sweet potatoes. 

In recent years, a number of workers have published amino acid analyses of the sweet potato (38, 43, 35, 22, 18). The overall picture is that the sweet potato amino acid pattern is of good nutritional quality but that the variability of individual amino acids both within the same cultivar and across cultivars is very high. For example, Walter et al. (44) reported that with the exception of aromatic amino acids, every essential amino acid has a score of less than 100 in one or more cultivars. The amino acid score is defined as the g of amino acid in 100 g of test protein divided by the number of g of that amino acid in the FAO/WHO reference pattern times 100. Bradbury et al. (22) showed that, for the same cultivar, environmental effects on the amino acid patterns is significant. For three cultivars, they found a mean percent standard deviation for all amino acids of 24.2,... 

The literature on concentrated sweet potato protein is sparse. Amino acid patterns for sweet potato protein isolates have been reported by three groups (16, 45, 46). One report showed that when compared to the FAO standard (47), no amino acids were limiting. The other reports showed total sulfur amino acids and lysine to be limiting (Table III). The patterns indicate a nutritionally well balanced protein. The improvement in nutritional quality, when compared to amino acid patterns from whole sweet potato, is due to the fact that whole sweet potatoes contain substantial amounts of NPN, which consists mainly of nonessential amino acids. This effectively dilutes the EAA and lowers the amino acid score. 

---