Interactions with Other Food Constituents

Strecker degradation, oxidation to indolylacetic acid and decarboxylation. The oxidative cleavage of skatole yields o-aminoacetophenone (cf. Formula 5.36), which has an animal odor and is the key aroma substance of tortillas and taco shells made of com treated with lime (Masa corn). In the case of milk dry products, o-aminoacetophenone causes an aroma defect (cf. 10.3.2). Its odor threshold of 0.2pg/kg (water) is very low. On the other hand, p-amino-acetophenone has an extremely high odor threshold of 100 mg/kg (water). 

Aroma interactions with lipids, proteins and carbohydrates affect the retention of volatiles within the food and, thereby, the levels in the gaseous phase. Consequently, the interactions affect the intensity and quality of food aroma. Since such interactions cannot be clearly followed in a real food system, their study has been transferred to model systems which can, in essence, reliably imitate the real systems. Consider the example of emulsions with fat contents of 1%, 5% and 20%, which have been aromatized with an aroma cocktail for mayonnaise consisting of diacetyl, (Z)-3-hexenol, (E,Z)-2,6-nonadienol, allyl isothiocyanate and allyl thiocyanate. The sample with 20% of fat has the typical and balanced odor of mayonnaise (Fig. 5.32 a). If the fat content decreases, the aroma changes drastically. The emulsion with 5% of fat has an untypical creamy and pungent odor since there is a decrease in the intensities of the buttery and fatty notes in the aroma profile (Fig. 5.32 b). In the case of 1% of fat, pungent, mustard-like aroma notes dominate (Fig. 5.32 c). 

Headspace analyses show that the drastic change in the aroma of the emulsions is based on the fact that the concentrations of the fatsoluble aroma substances (Z)-3-hexenol, allyl isothiocyanate and allyl thiocyanate in the gas phase increase with decreasing fat content (Fig. 5.33). Only the water-soluble diacetyl remains unaffected (Fig. 5.33). 

The concentration of the very aroma active (F,Z)-2,6-nonadienol (cf. 10.3.6) in the head space is below the detection limit. However, this odorant can be detected by headspace GC-olfactometry (cf. 5.2.2.2). The results in Table 5.36 show that this alcohol as well as (Z)-3-hexenol no longer contribute to the aroma in the 20% fat emulsion. In the emulsion with 1% of fat, (F,Z)-2,6-nonadienol, allyl isothiocyanate and allyl thiocyanate predominate and produce the green, mustard-like aroma (Table 5.36). 

A knowledge of the binding of aroma to solid food matrices, from the standpoint of food aroma-tization, aroma behavior and food processing and storage, is of great importance. 

---

The term functional properties has evolved to have a broad range of meanings. That corresponding to the term technological properties implies that the given component present in optimum concentration, subjected to processing at optimum parameters, contributes to the desirable sensory characteristics of the product, usually by interacting with other food constituents. Hydrophobic interactions,... 

The full extent to which saponins reduce cholesterol absorption requires further study. Because of the large number of saponins present in the food supply, it is possible that all of the mechanisms discussed earlier contribute to reduced cholesterol absorption. Unlike plant sterols in which their mode of action is relatively well defined, there are probably multiple effects of saponins within the intestinal tract, including their ability to interact with other dietary constituents and the ability of some saponins to be absorbed systemically. The regulatory effects of saponins on cellular cholesterol transport have not been examined. 

During food processing, interactions of antioxidants with proteins and other food constituents take place, and the activity of some antioxidants may change as a result of hydrolytical processes because glycosides and esters are converted... 

Texture is a sensory property of food. It arises from the food s physical structure, which is derived from the interactions of its constituent parts, and is perceived by monitoring how the structure responds to externally applied conditions. During development human beings learn to associate particular sensory responses from handling and eating foods, with specific textural characteristics. From verbal interactions with other humans they develop their textural vocabulary. The natural approach to characterising a food s texture is to ask human subjects to detail their assessments of texture. 

The behavior of minerals is often influenced by the presence of other food constituents. The recent interest in the beneficial effect of dietary fiber has led to studies of the role fiber plays in the absorption of minerals. It has been shown (Toma and Curtis 1986) that mineral absorption is decreased by fiber. A study of the behavior of iron, zinc, and calcium showed that interactions occur with phytate, which is present in fiber. Phytates can form insoluble complexes with iron and zinc and may interfere with the... 

Food flavor is a very important parameter influencing perceived quality. The volatile compounds contributing to the aroma of foods possess different chemical characteristics, such as boiling points and solubilities and the sensory properties of food cannot be understood only from the knowledge of aroma composition. This can be explained by interactions between flavor compounds and major constituents in food such as fat, proteins and carbohydrates (1). A number of different interactions has been proposed to explain the association of flavor compound with other food components. This includes reversible Van der Waals interactions and hydrogen bonds, hydrophobic interactions. The understanding of interactions of flavor with food is becoming important for the formulation of new foods or to... 

The knowledge of the composition of volatile compounds in food has greatly increased during the past decade. Many studies continue to report the identity and the concentration of volatile compounds in food matrices. However concentration alone appears insufScient to explain flavor properties of food. The lack of our knowledge concerning the influence of non-volatile constituents of food on the perception of aroma has to be filled by studies such as those presented in this paper. Data on interactions between aroma and matrix in wine are scarce compared with other food matrices studied. Flavor-matrix interactions in wine have generally been obtained in model systems and with instrumental experiments. However it is possible to develop some hypotheses on the possible sensory contribution of some non-volatile compounds of wine on overall aroma. 

Tomato lycopene and other carotenoids have been used as natural food constituents for a long time without toxicological considerations, in the same manner as other vegetable and fruit products. Lack of sound information regarding toxicology and bioavailability data limits the development of food safety regulations. Further studies are necessary to provide toxicological evaluation of lycopene and information on how lycopene interacts with other constituents. 

The chemical nature of food components is of crucial importance for all aspects of food quality. It decides on the nutritional value of the product, its sensory attractiveness, the development of desirable or deteriorative changes due to interactions with other constituents and to processing, and the susceptibility and resistance to spoilage during storage. Food components that contain reactive groups, many of them essential for the quality of the products, are generally labile and... 

Nutritional requirements, including nutritional interactions with other constituents of food (including other metals when the interactions are nutritionally or toxicologically relevant) in respect of, for instance, absorption, storage in the body, and elimination. 

Anthocyanins are a group of plant phenolics characterized by their blue-orange-red color. They have a double interest as plant constituents, one technological, since they can not only be used as natural colorants in the food industry but also can interact with other plant components influencing the final characteristics of the processed product, and the other is related to their implications on human health as they can be considered functional ingredients and have shown themselves as potential targets for the pharmacological industry. 

The properties of optically active polymer like its constituent monomers, microstructure and other parameters are very important. The bulk physical properties of the optically active polymers are determined by their basic stractures and it also describes behaviours like a continuous macroscopic material, e.g., simultaneous production of L-lactic acid with high optical activity and a soil amendment with food waste that demonstrates plant growth promoting activity [98]. Similarly, the bulk polymer interacts with other chemicals and solvents are described at the macro-scale. Chemical properties, at the nano-scale, describe how the chains interact through various physical forces. 

Various constituents in plant foods can impede Ca absorption. Plant-based diets can be high in oxalate and phytate, which are recognized as inhibitors of Ca absorption. In fact, Ca absorption is considered to be inversely proportional to oxalic acid content of the food (Weaver et al, 1999). Phytic acid poses Ca absorption problems for those species imable to endogenously synthesize phytase (e.g., humans, birds, and pigs). The Ca in CCM is chelated with the citrate and malate anions, which may make CCM less reactive than other sources of Ca toward food components known to interact with Ca " cations. For example, Lihono et al (1997a) reported data suggesting that the Ca in CCM may be less likely to complex with phytates than other Ca salts. Qn this basis, CCM may be more appropriate for the fortification of soy or other phytic acid-containing products. 

The methods employed to measure the interactions that occur between aroma compounds and other food or beverage constituents are frequently based on measuring changes in the vapour-liquid equilibrium when different macromolecules are present in the media. The determination of the gas-liquid partitioning with and without a food macromolecule is widely employed. 

Many drugs will cause adverse effects if the dose is excessive but some cause adverse effects at the correct dose in certain individuals. This can be due to an increased sensitivity of the patient because of genetic or other factors (see pp. 29-31). There may also be side effects which are not apparent at low or therapeutic doses but which become more important at higher doses. Occasionally, unexpected and serious adverse effects occur in a few patients. Sometimes this is due to an interaction between two drugs or between a drug and a food constituent such as occurred with the drug terfenadine (used to treat hay fever) and grapefruit juice (see case note, pp. 33-4). 

The water content of foods varies widely, and several properties of foods greatly depend on water content. This concerns, among other things, rates of changes—notably various kinds of deterioration—rheological properties, and hygroscopicity. The relations are far from simple, partly because water is not a simple liquid. Most of the intricacy relates to the many constituents in food, each of which may interact with water in a different way. 

Food deterioration can occur by means other than transport of gases into the food container or water into or out of the container. The loss of food characteristics in plastics packaging may also occur from direct interaction of the food with the polymer. The measurement of these types of transport is often termed organoleptic analysis because they may involve human taste tests. The tainting of food by transport of substances from the polymer into the food is termed migration. The loss of flavor constituents from the food into the polymer is termed scalping (32). Water content can affect these transport characteristics as well. 

---