Rodica Căpriţă

INFLUENCE OF TEMPERATURE ON THE EXTRACTIBILITY OF POLYSACCHARIDES IN WHEAT

Rodica Căpriţă, A. Căpriţă, Iuliana Creţescu, C. Julean

Abstract
Wheat increases the viscosity of contents in the intestine of birds, and consequently decrease the nutrient utilization. The nutritional value of wheat is not related to the amount of insoluble arabinoxylans, but it is correlated with the content of soluble arabinoxylans. Therefore, the viscosity value of the wheat water extract is more important in estimating nutrient composition than the composition of the cell walls. Our experiments had in view the effect of temperature on the soluble fraction of non-starch polysaccharides (NSPs). The heating of the samples at 60°C and 80°C, before extraction, resulted in the decrease of the soluble NSPs, as evidenced by the dynamic viscosity variation. Heating the wheat samples for 15 minutes at 80°C deactivates the endogenous hydrolytic enzymes.

Key words: non-starch polysaccharides, dynamic viscosity, wheat


INFLUENŢA TEMPERATURII ASUPRA EXTRACTABILITĂŢII POLIGLUCIDELOR DIN GRĀU

Rodica Căpriţă, A. Căpriţă, Iuliana Creţescu, C. Julean

Rezumat
Grāul produce cresterea vāscozitatii continutului intestinal la pasari si īn consecinta reduce gradul de utilizare a nutrientilor. Valoarea nutritiva a grāului nu este legata de cantitatea de arabinoxilani insolubili, ci este corelata cu continutul īn arabinoxilani solubili. De aceea, vāscozitatea extractelor apoase din grāu este mult mai importanta, īn aprecierea valorii nutritive, decāt compozitia peretilor celulari. Experimentele efectuate au urmarit efectul temperaturii asupra fractiunii solubile de poliglucide neamidonoase (PNA). Īncalzirea probelor la 60°C si 80°C īnaintea extractiei are ca efect o scadere a fractiunii solubile a poliglucidelor, evidentiata prin variatia vāscozitatii dinamice. Īncalzirea timp de 15 minute la 80°C a probelor de grāu dezactiveaza enzimele endogene hidrolitice.

Cuvinte cheie: poliglucide neamidonoase, vāscozitate dinamica, grāu