Читать книгу Polysaccharides - Группа авторов - Страница 112

The FDA (Food and Drug Administration) declared agar as GRAS (Generally Recognized as Safe) in USA. Globally agar is used in a lot of food stuff. It is considered as E406 food additive in Europe. Agar can be found as 9002-18-0 compound in chemical abstracts. It is important to take care of different synergies when dealing with the agar gel. The synergy between agar and locust bean gum in Pterocladia and Gelidium improves the inflexibility and texture, making it additionally palatable due to the elasticity conferred. This synergy also helps in removing the brittleness as well as making the gel less hydrophobic during managing, shipping and storage of the gel. On the other hand synergies of Gracilaria agars with sugars, increases their gelling strength. This occurs only when sugar level is more than 60%, like in jams and jellies.

Gel drying due air exposure, can be restricted with the use of glycerol or sorbitol in aqueous phase of agar gel preparation. The ambient temperature of agar changes during its life and affects the gel behavior. Agar is tasteless and it is hard to taste it in food stuffs with subtle flavour. However the food stuffs which require cation (like calcium, carragenate, potassium, alginate, etc.) to gel, should be adjoined with strong flavor. Because these cations have stronger taste compared to the agar, and has to be cover up with strong flavors.

Table 5.3 Region-wise global agar applications [31].

Application/ product	Geographical areas
	US/Europe	Latin America	Asia
Jams and jellies	Present	Present	Present
Processed cheese	Present	Information not available	Absent
Farm and dairy products	Present	Present	Present
Wine clarification	Present	Present	Information not available
Gelled meats	Present	Information not available	Present
Dulce de batata	Absent	Present	Absent
Mitsumame	Absent	Absent	Present
Red bean jelly	Absent	Absent	Present
Agar jelly beverages	Present	Present	Present
Ice cream	Present	Present	Present
Milk shakes	Present	Present	Present
Sherbet	Present	Present	Present
Custard pudding	Present	Present	Present
Cakes	Present	Present	Present
Pie filling	Present	Present	Absent
Flat icing	Present	Present	Present
Meringue	Present	Absent	Absent
Cookies	Present	Present	Present
Candy (agar jelly)	Present	Present	Present
Fruit jelly dessert	Present	Present	Present

Mitsumame, a fruit dish of Portugal and Japan, requires agar with elevated melting point. Sometimes acidification is required in food processing and needs to be done only at lower temperature and when agar is completely dissolved, since it can hydrolyze the agar in food. Likewise, the aromas should be added only when product is complete to avoid evaporation loss. However, agar has lower degree of hydrolysis even at high temperature. It is noticeable that during meat preservation, sterilization is required and is done at 121 °C, still agar doesn’t get hydrolyzed. An average of 0.5 to 1.5% agar is added to foods, since human digestive system cannot absorb much of it. It is reported that less than 10% of ingested agar is digested.

This encourages the use of agar in dieting industry. Moreover it doesn’t get digested and has no impact upon human health and can be used as dietary food stuff for diabetic patients. Unlike pectin, which requires sugars to gel, agar can be easily used as food stuff in medical industry. Like in diabetic patients, artificial sweeteners, as sugar substitute, can be added to agar to create a very least calorie food. Region-wise global agar applications in food industries are given in Table 5.3.