Flaxseed Soluble Dietary Fibre Enhances Lactic Acid Bacterial Survival and Growth in Kefir and Possesses High Antioxidant Capacity

Abstract

This study investigated the capability and efficiency of flaxseed soluble dietary fibre /mucilage to enhance bacterial survival and growth in kefir as well as the antioxidant activity of the mucilage. Crude flaxseed mucilage was extracted using a microwave method, followed by enzymatic and dialysis treatments to obtain pure mucilage. The antioxidant activities of the pure and crude mucilage were measured using different assays. Microbial analyses, pH and total titratable acidity (TTA) were measured in kefir samples, supplemented with probiotic bacteria (Lactobacillus acidophilus and Bifidobacterium lactis) and pure or crude flaxseed mucilage during 28 cold storage periodat 4 ºC. The results showed that for all kefir samples, the total bacteria counts were above7.9 log cfu/mL at the end of cold storage period. However, kefir samples supplemented with pure flaxseed mucilage enhanced significantly (P < 0.05) higher viability of bacteria (9.5 log cfu/mL) and acidity (0.78% TTA). An overall pH decline of 0.2 was observed during cold storage period. The total phenolic content (TPC) in crude mucilage was significantly (P < 0.05) higher than pure mucilage (10.5 ± 0.2 and 5.7 ± 0.1 mg Gallic acid equivalent /g flaxseed, respectively). The mucilage from crude flaxseed exhibited strong antioxidant activity; Oxygen Radical Absorbance Capacity (ORAC) value of 51.2 ± 3.3 μmol Trolox equivalent /g, 53.7 ± 2.8% discoloration for 2,2-diphenyl-1-picrylhydrazyl (DPPH), and 68.3 ± 9.2% β-Carotene bleaching which was well in agreement with high TPC. This study demonstrated that flaxseed mucilage acts as a good source of prebiotic, enhancing lactic acid bacteria growth in kefir model in addition of their high antioxidant beneficiary.

Physicochemical, Microbiological Quality and Organoleptic Properties of Yoghurt Supplemented with Linseed Oil

“…On the contrary at day 14, yoghurt samples supported with linseed oil and control provided lower total count of bacteria. The observed decrease in bacteria growth could be due to the decrease in the amount of remaining sugar in yoghurt and resulting in fewer nutrients for their growth promotion (Nezhad et al, 2013). Data presented in Table (4) shows that the total coliforms were not detected in all samples either fresh or during the cold storage period.…”

Assessment of antioxidant capacity by method comparison and amino acid characterisation in buffalo milk kefir

“…These components show antioxidative effects by scavenging‐free oxygen/nitrogen radicals, chelating pro‐oxidative metal ions, inhibiting lipid peroxidation and ascorbate autoxidation (Nezhad et al . ; Unal et al . ; Bensmira and Jiang ; Najgebauer‐Lejko and Sady ; Shanmugam et al .…”

“…The kefir starter cultures themselves and metabolites of the microorganisms formed during fermentation of kefir lead to the formation, not only of lactic acid, acetic acid, ethanol and carbon dioxide, but also the release of new milk-associated antioxidant micronutrients such as organic acids, amino acids, vitamins (E, B 3 , B 6 , B 12 ), minerals (Se, Fe, Zu, Mn) and enzymes (glutathione peroxidase, catalase and superoxide dismutase). These components show antioxidative effects by scavenging-free oxygen/nitrogen radicals, chelating pro-oxidative metal ions, inhibiting lipid peroxidation and ascorbate autoxidation (Nezhad et al 2013;Unal et al 2013;Bensmira and Jiang 2015;Najgebauer-Lejko and Sady 2015;Shanmugam et al 2015;Sabokbar and Khodaiyan 2016). The major factors affecting the antioxidative properties of kefir are the chemical composition of the milk, its heat treatment, the ratio and type of starter culture, fermentation, cooling and storage conditions (e.g.…”

The Fatty Acid Profile and Phenolic Composition of Descurainia sophia Seeds Extracted by Supercritical CO2

“…Antioxidant capacity of the extracted phenolics was evaluated by measuring total phenolic content (TPC), oxygen radical absorbance capacity (ORAC), and with a β-carotene bleaching assay as described previously [19]. All analyses were conducted in triplicate.…”