Changes in the fat fraction of durable sweet baked products were assessed by determining contents of peroxides, cinnamic and malonic aldehydes, fatty acids, and the ester number. Three kinds of biscuits and one kind of wafer were studied in various temperature and air humidity conditions over a period of four months.
Potato, wheat and maize starches were cross-linked with urea in the presence of sulphuric acid, and hydroxypropylammonium starches were obtained from them. The physico-chemical properties of the obtained modified starch preparations were studied.
W pracy badano wpływ temperatury i ziarnistości skrobi ziemniaczanej na proces jej dekstrynizacji. W retorcie laboratoryjnej prażono próbki skrobi zakwaszonej kwasem azotowym oraz próbki skrobi niezakwaszonej. Temperatura prażenia wynosiła 130-210°C. Otrzymane dekstryny badano oznaczając ich kwasowość, pH, rozpuszczalność i lepkość roztworów. Stwierdzono, że ze wzrostem temperatury prażenia proces dekstrynizacji znacznie przyspiesza się. Badając wpływ wielkości ziarn skrobi stwierdzono, że małe ziarenka ulegają dekstrynizacji najwolniej, a duże najszybciej. Zaobserwowany przyrost kwasowości dekstryn w czasie prażenia, związany z podwyższaniem temperatury procesu, był szczególnie widoczny u dekstryn otrzymanych ze skrobi niezakwaszonej.
Starch ethers were obtained under various conditions, i.e. hydroxypropylammonium starch as cationic starch and hydroxypropyl starch. The degree of substitution of starch ethers and their properties were examined.
Starch was modified with the use of urea in presences of magnesium sulphate and sulphuric acid or phosphoric acid. The influence of various factors on the physico-chemical properties of modified starch was examined.
High saccharified syrups (50-75DE) were obtained by liquefaction of potato starch with α-amylase and saccharification with glucoamylase. Considerably reduced concentrations of glucoamylase preparations were used in hydrolysates to make the process more economical. A part of the experiments concerned enzymatic dissolving and saccharification of starch at constant pH 6. This was performed to avoid accretion of salts, which would have developed in an environment with varying pH.
Using various enzyme preparations it was possible to obtain starch hydrolysates of a concentration of 30-50% d.s. and a saccharification level of 38-77 DE. PH was kept at the constant value of 5,5 both during the dissolution and the saccharification of starch. During the saccharification stage, two enzymes i.e. bacterial α-amylase and glucoamylase, cooperated with each other.