Functional wheat bread with calcium chelate complexes

Abstract

Bakery products are promising objects for enrichment with functional food ingredients, as they are mass consumption products. The problem of hypo-elementosis in people makes it advisable to develop functional food ingredients based on easily digestible and safe forms of essential biometals, including calcium. In this study, it has been shown that wheat bread can be enriched with calcium chelate complexes. This functional food ingredient was obtained by complexation of Ca2+ with bioligands of probiotic origin, followed by immobilizing the complexes on dietary fiber of wheat bran. Mixed-ligand systems were obtained by combining a metabolite (lactic acid) and degradation products of peptidoglycans of Lactobacillus delbrueckii subsp. Bulgaricus B-3964. The peptidoglycans of the biomass autolysate were degraded by enzymatic hydrolysis with papain. This resulted in obtaining a mixture that contained amino acids, low molecular weight peptides, and muropeptides, in the concentrations 12.44 mg/cm3, 6.85 mg/cm3, and 2.76 mg/cm3, respectively. The nephelometric method has shown that this mixed-ligand system binds calcium ions in an amount of 18 mg/cm3. The soluble complexes obtained were immobilized on the dietary fiber to solve the problem of concentrating, drying, and dosing these ingredients. It has been proved that immobilization only occurs due to physical sorption that completely releases the active component from the dietary fiber matrix under conditions that simulate the gastrointestinal environment. The functional ingredient developed was added to the classic wheat bread recipe, where it replaced 1 %, 3 %, and 5 % of the flour. Bread was made without pre-fermentation to reduce the total production time and to prevent the ingredient’s biologically active components from being assimilated by yeast during long fermentation. The study of the experimental and control samples of wheat bread has shown that the introduction of chelate complexes of calcium immobilized on dietary fiber causes no deterioration of the physico-chemical parameters of the finished bread: they are all within the limits approved by the regulatory documentation. The sensory properties of the samples with 1 % and 3 % of flour replaced are close to those of the control sample. So 3 % of the ingredient is the recommended amount to be added, as it provides 98 % of the daily requirement of calcium as a functional ingredient and covers about 25 % of the daily allowance of dietary fiber.