Impact of coffee silverskin on in-vitro viability of kefir culture during storage

Probiotic dairy products must contain a certain level of live probiotic microorganisms at the time of consumption. The number of live microorganisms in kefir culture, which is a mixture of different microorganisms, may change during storage due to various factors. In this study, the effects of adding a novel ingredient coffee bean membrane (CSS-coffee silverskin), on the viability of microorganisms contained in kefir culture were investigated. For this purpose, CSS obtained from 2 different coffee varieties (Arabica and Robusta) was added to kefir samples at 3 different concentrations (0.5, 0.75 and 1.0 %) at the beginning of fermentation. It was observed that especially the addition of CSS belonging to the Robusta variety significantly increased the viability of lactic acid bacteria (lactobacilli and lactococci) which accounted for 88-94.10 % and 82.37-92.44 % respectively. During the storage period of 28 days at 4 °C; it could be observed that kefir enrichment with CSS of both coffee varieties increased the viability of lactobacilli and lactococci after in-vitro digestion, depending on the rate of supplementation. Number of yeasts was decreased during the storage.

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Screening of antifungal lactic acid bacteria as bioprotective cultures in yogurts and whey beverage

Journal of Food Protection ◽

10.4315/jfp-20-441 ◽

2021 ◽

Author(s):

Rihua Xu ◽

Ren Sa ◽

Junwei Jia ◽

Lanlan Li ◽

Xiao Wang ◽

...

Keyword(s):

Lactic Acid ◽

Antifungal Activity ◽

Lactic Acid Bacteria ◽

Dairy Products ◽

Fungal Growth ◽

Storage Period ◽

Industrial Applications ◽

In Vitro Tests ◽

In Situ Tests

The demand for “preservative-free” food products is rising, and biopreservation seems to be a potential alternative to replace or reduce the use of chemical preservatives. This study’s objective was to assess the antifungal activity of lactic acid bacteria (LAB) (n = 98) and the efficacy and applicability of the chosen bioprotective cultures against fungal spoilers in dairy products. First, 14 strains of antifungal strains were preliminarily screened by in vitro tests against Pichia pastoris D3, Aspergillus niger D1, Geotrichum candidum N1, Kluyveromyces marxianus W1, and Penicillium chrysogenum B1 and validated by challenge tests in yogurts, indicating that the fungal-inhibiting activity of LAB was species specific and yogurts fermented with antifungal LAB cultures were more effective in extending the shelf life. Secondly, the chosen 14 LAB strains were identified by the 16SrDNA sequence analysis and carbohydrate fermentation test. The results were as follows: 9 strains were Lactobacillus plantarum , 3 were Lactobacillus paracasei , 1 was Enterococus faecium , and 1 was Lactobacillus rhamnosus. Among them, active L. plantarum N7 was the chosen and studied factor that affects the antifungal activity using the response surface methodology (RSM). Finally, in situ tests were conducted to validate the activity of L. plantarum N7 in actual dairy products (whey beverage). Physicochemical and microbial indices of whey beverage during storage period exhibited that antifungal L. plantarum N7 could slow the fungal growth and be candidates of interest for industrial applications.

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Tolerance of autochthonous lactic acid bacteria to different processing conditions in vitro

Food and Feed Research ◽

10.5937/ffr47-29426 ◽

2020 ◽

Vol 47 (2) ◽

pp. 119-129

Author(s):

Mirjana Grujović ◽

Katarina Mladenović ◽

Ljiljana Čomić

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Dairy Products ◽

Starter Cultures ◽

Processing Conditions ◽

Dairy Processing ◽

Nacl Concentration ◽

Different Temperatures

In this paper, the effect of different temperatures, pH, and NaCl concentration on the growth of autochthonous lactic acid bacteria isolated from traditionally made Serbian cheese (Sokobanja area) was investigated by using the spectrophotometric method. Growth of tested Lactobacillus (Lb. fermentum, Lb. plantarum, and Lb. brevis) and Lactococcus lactis subsp. lactis biovar. diacetylactis five isolates were better in acidic pH, while the growth of Enterococcus isolates (E. durans, E. faecium, and E. faecalis) was better in basic pH, at 37 °C. At 4 °C after 24 h, none of the tested bacteria showed growth. Since the autochthonous isolates were tolerant to a tested range of dairy processing conditions, further studies need to include the characterization of enzymatic activity of selected isolates, as well as the ability to use these isolates like starter cultures or food supplements in dairy or non-dairy products.

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Co-Microencapsulation of Flavonoids from Yellow Onion Skins and Lactic Acid Bacteria Lead to Multifunctional Ingredient for Nutraceutical and Pharmaceutics Applications

Pharmaceutics ◽

10.3390/pharmaceutics12111053 ◽

2020 ◽

Vol 12 (11) ◽

pp. 1053

Author(s):

Ștefania Adelina Milea ◽

Mihaela Aida Vasile ◽

Oana Crăciunescu ◽

Ana-Maria Prelipcean ◽

Gabriela Elena Bahrim ◽

...

Keyword(s):

Lactic Acid ◽

Lactic Acid Bacteria ◽

Value Added ◽

Dry Weight ◽

Natural Antioxidants ◽

In Vitro Digestion ◽

Inhibitory Effect ◽

Coating Materials ◽

Yellow Onion

In this study, flavonoids extracted from yellow onion skins and Lactobacillus casei were encapsulated in a combination of whey protein isolate, inulin and maltodextrin with an encapsulation efficiency of 84.82 ± 0.72% for flavonoids and 72.49 ± 0.11% for lactic acid bacteria. The obtained powder showed a flavonoid content of 89.49 ± 4.12 mg quercetin equivalents/g dry weight (DW) and an antioxidant activity of 39.27 ± 0.45 mM Trolox/g DW. The powder presented a significant antidiabetic and anti-inflammatory potential, with an inhibitory effect on α-amylase, lipase and lipoxygenase of 76.40 ± 2.30%, 82.58 ± 3.36% and 49.01 ± 0.62%, respectively. The results obtained for in vitro digestion showed that the coating materials have a protective effect on the flavonoids release. Cytotoxicity results indicated that the powder was cytocompatible up to a concentration of 500 μg/mL. The functional potential of the powder was tested by adding in a selected food matrix, highlighting a good stability of the phytochemicals, whereas an increase with 1 log cell forming unit (CFU)/g DW was observed after 21 days of storage. The obtained results are promising in the valorization of natural antioxidants in combination with lactic acid bacteria in order to develop multifunctional ingredients with value-added for food and pharmaceutics applications.

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