Enhanced probiotic viability and aromatic profile of yogurts produced using wheat bran (Triticum aestivum) as cell immobilization carrier

Abstract

The effect of wheat bran (Triticum aestivum) as a cell immobilization carrier for probiotic yogurt production on cell viability, composition of volatile compounds and sensory characteristics, was studied. Wheat bran was delignified and separately used as a carrier for the immobilization of Lactobacillus casei ATCC393 and Lactobacillus bulgaricus DSM20081. Both biocatalysts were freeze-dried without the addition of cryoprotectants and were used for yogurt fermentation at 40 • C. Their operational stability was evaluated during successive yogurt fermentation batches until they were inactivated. The yogurts fermented using the immobilized biocatalysts were compared with those fermented with free Lactobacillus cells and with conventional yogurt culture (Streptococcus thermophilus and L. bulgaricus). The novel yogurts showed significantly higher cell viabilities during storage at 4 • C. In addition, the immobilized biocatalysts showed higher survival rates during exposure to simulated gastric juice (pH 3.0). The immobilized biocatalysts significantly affected the production of volatile compounds, indicating, in combination with the sensory evaluations, potential for good-quality probiotic yogurt production by freeze-dried ready-to-use immobilized starters.

Growth Capacity of a Novel Potential Probiotic Lactobacillus paracasei K5 Strain Incorporated in Industrial White Brined Cheese as an Adjunct Culture

“…More specifically, wheat bran contains xylo‐oligosaccharides (XOS) which can significantly enhance human immune system by enhancing the growth of probiotic bacteria (Gullón et al., ; Mäkeläinen, Saarinen, Stowell, Rautonen, & Ouwehand, ; Ravn et al., ; Sapirstein, ). The latest reports confirm the effectiveness of immobilization on viability of lactic acid bacteria for the production of probiotic dairy products (Bosnea et al., ; Schoina et al., ; Terpou et al., ).…”

“…Small particles (0.5 g) of freeze‐dried (Terpou et al., ) delignified wheat bran with immobilized cells of L. paracasei K5 were coated with gold in a Balzers SCD 004 Sputter coater (Bal‐Tec, Schalksmühle, Germany) for 2 min. The samples were examined in a JSM‐6300 scanning electron microscope (JEOL, Tokyo, Japan), operated at an accelerating voltage of 20kV.…”

“…Prebiotics are non‐digestible food ingredients that can benefit the host by stimulating the growth of probiotic bacteria in order to successfully colonize to the intestine, improving the health of the hosts (Anadón, Martínez‐Larrañaga, Arés, & Martínez, ; Kumar, Nagpal, Hemalatha, Yadav, & Marotta, ). There is a great interest in finding prebiotic‐rich food matrices like wheat bran which is a byproduct during flour production and has been successfully used as an immobilization support for the production of probiotic dairy products (Terpou, Bekatorou, Kanellaki, Koutinas, & Nigam, ; Terpou et al., , ). More specifically, wheat bran contains xylo‐oligosaccharides (XOS) which can significantly enhance human immune system by enhancing the growth of probiotic bacteria (Gullón et al., ; Mäkeläinen, Saarinen, Stowell, Rautonen, & Ouwehand, ; Ravn et al., ; Sapirstein, ).…”

Enhanced Aromatic Profile and Functionality of Cheese Whey Beverages by Incorporation of Probiotic Cells Immobilized on Pistacia terebinthus Resin

“…Selected whey beverages were analyzed after 30 days of storage (at 4 • C) and compared with control samples (C). For solid-phase microextraction gas chromatography/mass spectrometry (SPME GC/MS) analysis, 7 mL of beverage samples (B2, C) were collected and mixed with 3 g of salt (Sigma-Aldrich Ltd., St Louis, USA) [36]. The samples were placed into a 20-mL headspace vial, which was sealed with a rubber septum and heated in a water bath for approximately 5 min for the temperature to be stabilized at 60 • C. Then, each sample was heated (60 • C) for 45 min, while the SPME needle (bearing a 2-cm fiber, 50/30 mm DVD/Carboxen/PDMS Stable Flex Supelco, Bellefonte, state of Pennsylvania, USA) was inserted through the septum, and the fiber was exposed to the headspace.…”

“…casei ATCC 393 is a probiotic bacterium that has been added in many dairy products such as cheeses [22,37], fermented beverages [38], frozen desserts [19], and yogurts [39]. The selected strain has been applied either as a starter or as an adjunct probiotic culture mainly due to its health potential and its stability during manufacture and storage as well as due to its high survival rates reported under simulated gastrointestinal conditions [19,36]. In vitro and preliminary in vivo studies have demonstrated that L. casei ATCC 393 displayed several probiotic properties such as cholesterol removal in parallel with pathogens reduction and more importantly distinct adhesion in rat intestinal mucosa [40,41].…”