engleski

Staling kinetics of bread supplemented with enzymes, hydrocolloids and emulsifers

Bread staling process involves several physico-chemical changes that produce different undesirable properties like firmness increase, drying of bread crumb, odour changes etc. It is considered that the most responsible process for bread staling at the molecular level is starch retrogradation, mainly amylopectin retrogradation from amorphous to semi-crystalline state. The objective of this research was to investigate influence of maltogenic α -amylase, 1, 3-specific lipase with both lipase and phospholipase activity, hydrocolloid carboxymethylcellulose (CMC) and emulsifier diacetyl tartaric acid ester of monoglyceride (DATEM) on bread staling process The following analyses were conducted during seven days of bread storage: determination of amylopectin recrystalisation with differential scanning calorimetry (DSC), texture profile analyses (TPA) and amylographic investigation of bread slurries. Non-linear estimation of experimental data was carried out according to Avrami model of polymer crystallisation. The greatest influence on texture of fresh samples and the smallest change of firmness, resilience and cohesiveness during staling were caused by combined addition of α -amylase and lipase. Synergistic effect of these enzymes was confirmed by DSC determination of retrogradation enthalpy Δ H. Decrease of breakdown viscosity was the most noticeable change of amylografic parameters during bread staling.

bread staling; amylopectin retrogradation; texture profile analyses; thermophysical properties; amylographic studies of bread crumb

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