scholarly journals Evaluation of Yoghurts with Thyme, Thyme Essential Oil and Salt

2018 ◽  
Vol 66 (2) ◽  
pp. 365-369
Author(s):  
Viera Ducková ◽  
Miroslav Kročko ◽  
Vladimíra Kňazovická ◽  
Margita Čanigová
Keyword(s):  
Lactic Acid ◽  
Essential Oil ◽  
Bitter Taste ◽  
Control Sample ◽  
Titratable Acidity ◽  
Coliform Bacteria ◽  
Thymus Vulgaris ◽  
Fermentation Time ◽  
Ph Values ◽  
Thyme Essential Oil

The aim of this work was production and evaluation of yoghurts with different addition of thyme (Thymus vulgaris), thyme essential oil (EO) and salt. It was produced: control yoghurt, yoghurt with 0.45 % of salt and 0.25 % of thyme, yoghurt with 0.90 % of salt and 0.50 % of thyme, yoghurt with 0.45 % of salt and 0.004 % of thyme EO, yoghurt with 0.90 % of salt and 0.008 % of thyme EO. The time of yoghurt fermentation was extended from the previous 3.5 hours (control sample) to 5 hours for samples with thyme or even up to 7 hours for samples with thyme EO. The fermentation time also depended on the concentration of the used substances. The average titratable acidity of yoghurts fluctuated from 46.52 °SH to 49.51 °SH at day after the production and from 51.57 °SH to 55.75 °SH after 7 days of storage. Average pH values of yoghurts fluctuated from pH 4.77 to pH 4.81 at day after production and from pH 4.48 to pH 4.63 after storage. In all samples of yoghurts were not detected coliform bacteria (< 10 CFU.g-1). The yeasts were appeared rarely (101 CFU.g-1), and their numbers were increased during cold storage (102 up to 103 CFU.g-1). Moulds appeared rarely (101 CFU.g-1). The number of lactic acid bacteria reached required minimum value of 107 CFU.g-1. Samples of yoghurts reached characteristic yoghurt and thyme aroma. The intensity of sour, salty and thyme taste, determined by sensory evaluation was in experimental samples of yoghurts at different level. A higher concentration of thyme and thyme EO gave to yoghurts a bitter taste. The dense consistency of the yoghurts was decreased with the increased addition of thyme and thyme EO. According to results, we recommend the recipe of yogurt with 0.45 % of salt and 0.25 % of thyme or 0.004 % of thyme EO.

scholarly journals Development of Kefir beverages: Standardization of process parameters

2016 ◽  
Vol 7 (2) ◽  
pp. 80
Author(s):  
Jaqueline Gilmara Barboza Januário ◽  
Tailana Marin de Lima ◽  
Daiane Aparecida Camargo Portella ◽  
Caroline Barboza Januário ◽  
Suellen Jensen Klososki ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Factorial Design ◽  
Process Parameters ◽  
Titratable Acidity ◽  
Central Point ◽  
Sensory Characteristics ◽  
Acidic Ph ◽  
Fermentation Time ◽  
23 Factorial Design ◽  
Kefir Grains

This study aimed to characterize physico-chemically Kefir grains and standardize the process parameters of the beverages, in order to obtain an optimum product. Kefir grains consisted basically of water (85.61 ± 0.41%) and had an acidic pH (4.45) and low acidity (0.44 ± 0.09% lactic acid). To determine the process parameters, it was used a 23 factorial design with three replications at the central point, being evaluated the amount of grain (2-6%), amount of sugar (10-14%) and fermentation time (18-24 hours) at 25oC. The amount of sugar or grains had no influence on the pH and titratable acidity. A longer fermentation time (24 hours) resulted in products with pH and acidity within the recommended values, while fewer grains (2%) did not result in too firm beverages. The formulation with the best physicochemical and sensory characteristics had 2% grain, 10% sugar and 24 hours of fermentation, being described as creamy, slightly acidic and with intermediate sweetness.

scholarly journals Impact of yeast sediment beta-glucans on the quality indices of yoghurt

Food systems ◽  
2021 ◽  
Vol 4 (1) ◽  
pp. 12-18
Author(s):  
A. I. Chirsanova ◽  
A. V. Boistean ◽  
N. Chiseliță ◽  
R. Siminiuc
Keyword(s):  
Physicochemical Properties ◽  
Glycemic Index ◽  
Control Sample ◽  
Titratable Acidity ◽  
Laboratory Method ◽  
Beta Glucan ◽  
Food Category ◽  
Fermentation Time ◽  
Beta Glucans ◽  
Low Glycemic Index

The objective of the study was to investigate the potential application of beta-glucans obtained from yeast sediment resulting from the manufacture of local Viorica wine (2018 harvest). To determine the amount of beta-glucans in the yeast sediment, two were used: the calculation method and the laboratory method, obtaining similar quantities, 29.92 ± 0.47 and 28.17 ± 0.32 respectively. The beta -glucans obtained were incorporated in various concentrations (0.1%; 0.2%; 0.3%; 0.4% and 0.5%) in the yogurt obtained from skimmed milk. The effect of beta-glucan addition on the physicochemical properties of freshly prepared yogurts was investigated. The addition of beta-glucans positively influenced the formation of the gel relay resulting in a decrease in the fermentation time of yogurt. The final pH point of 4.5 was reached one hour earlier (in 4 hours) compared to the control sample (in 5 hours). The results showed that there are no significant changes in physicochemical properties (titratable acidity, pH, viscosity and syneresis). The results obtained report that beta-glucans can be used as a thickening agent for low-fat yogurts by shortening the fermentation period and not essentially changing the sensory characteristics. Experimental results showed that the glycemic index of yogurt samples with the addition of beta-glucans have similar values in the range of 28-30. Respectively, the yogurts under study are attributed to food category with low glycemic index.

scholarly journals Antifungal potential of thyme essential oil as a preservative for storage of wheat seeds

2017 ◽  
Vol 76 (1) ◽  
pp. 64-71 ◽  
Author(s):  
Sabina Anžlovar ◽  
Matevž Likar ◽  
Jasna Dolenc Koce
Keyword(s):  
Seed Germination ◽  
Essential Oil ◽  
Fungal Infections ◽  
Fungal Growth ◽  
Thymus Vulgaris ◽  
Wheat Grain ◽  
Surface Sterilization ◽  
Thyme Essential Oil ◽  
Indirect Treatment ◽  
Grain Surface

AbstractPlant essential oils are potential food preservatives due to their inhibitory effects on bacterial and fungal growth. Antifungal activities of common thyme (Thymus vulgaris) essential oil were tested against endophytic fungi grown from wheat (Triticum aestivum) grain, molecularly identified as Alternaria alternata, Alternaria infectoria, Aspergillus flavus, Epicoccum nigrum and Fusarium poae. Their susceptibility to thyme essential oil was tested in vitro, and ranged from fungicidal to fungistatic. Treatment combinations of prior grain surface sterilization with hypochlorite and direct/indirect treatment with the essential oil were used, which showed strong effects on infection incidence and germination. Direct soaking of the wheat grain in the essential oil was particularly effective, but inhibited both fungal growth and seed germination. In contrast, indirect treatment of the grain with the essential oil (i.e., fumigation) inhibited fungal growth without negative effects on seed germination. In combination with grain surface sterilization with hypochlorite, indirect treatment with thyme essential oil reduced these fungal infections even more. Since thyme essential oil is safe for plants and consumers, in the form of fumigation it could be used as a protectant of storage containers for wheat grain intended for sowing and for food production.

scholarly journals Effects of Lactic Acid Fermentation on the Retention of Β-Carotene Content in Orange Fleshed Sweet Potatoes

2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Benard O. Oloo ◽  
A. A. Shitandi ◽  
S. Mahungu ◽  
J. B. Malinga ◽  
Rose B. Ogata
Keyword(s):  
Lactic Acid ◽  
Sweet Potato ◽  
Titratable Acidity ◽  
Lactic Acid Fermentation ◽  
Process Conditions ◽  
Sweet Potatoes ◽  
Acid Fermentation ◽  
Carotene Content ◽  
Fermentation Time ◽  
Β Carotene

This study aimed to establish the effects of lactic fermentation on the levels of β-carotene in selected  orange fleshed sweet potato (OFSP) varieties from Kenya.  Furthermore,it sought to demonstrate fermentation as a potential process for making new products from sweet potato with enhanced nutraceutical attributes. The varieties (Zapallo, Nyathiodiewo and SPK004/06) were fermented with Lactobacillus plantarum MTCC 1407 at 25 ± 2°C for 48 h and kept for 28 days to make lacto-pickles. During fermentation both analytical [pH, titratable acidity (TA), lactic acid (LA), starch, total sugar, reducing sugar (g/kg roots), texture (N/m2), β-carotene (mg/kg roots)] and sensory (texture, taste, flavour and after taste) attributes of sweet potato lacto-juice were evaluated. Process conditions were optimized by varying brine levels, with fermentation time. A UV-visible spectrophotometer was used to identify and quantify β-carotene. Any significant variations (p < 0.05) in analytical attributes between the fermented and unfermented samples (pH, LA, TA and β-carotene concentration) of lacto-pickles, prepared from the potato roots, were assessed. The study reported a final composition of 156.49mg/kg, 0.53mg/kg, 0.3N/m2, 1.3g/kg, 5.86g/kg, 0.5g/kg and 5.86g/kg for β-carotene, Ascorbic acid, texture; Starch, total sugars, LA and TA respectively, and a pH of 3.27. The fermented products were subjected to flavour profiling by a panel. The product sensory scores were 1.5 to 2.5 on a 5 point hedonic scale, ranging from dislike slightly to like much. The products with brine levels at 4 and 6% were most preferred. The retention of β-carotene was 93.97%. This demonstrated lactic acid fermentation as a better method for processing OFSP as the main nutritional attributes are retained. The final product was resistant to spoilage microorganisms after 28 days of fermentation. Further preservation could be obtained by addition of sodium metabisulphite. In conclusion, Lactic acid fermentation using L. plantarum is a novel method of producing Lacto pickles from Zapallo OFSP, with 93.97% β-carotene retention and adequate shelf life.

Antimicrobial Effect of Medicinal Plants on Microbiological Quality of Grape Juice

2021 ◽  
Vol 5 (1) ◽  
pp. 28-35
Author(s):  
Miroslava Kačániová ◽  
Jakub Mankovecký ◽  
Lucia Galovičová ◽  
Petra Borotová ◽  
Simona Kunová ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Medicinal Plants ◽  
Control Sample ◽  
Microbiological Quality ◽  
Grape Juice ◽  
Coliform Bacteria ◽  
Cabernet Sauvignon ◽  
Microscopic Fungi

Abstract The safety of plant-based food of plant origin is a priority for producers and consumers. The biological value of food products enriched with herbal ingredients is getting more popular among consumers. The present study was aimed to evaluate microbiological quality of grape juice enriched with medicinal plants. There were two varieties of grapes -Welschriesling and Cabernet Sauvignon and six species of medicinal plants used for the experiment: Calendula officinalis L., Ginkgo biloba, Thymus serpyllum, Matricaria recutita, Salvia officinalis L., and Mentha aquatica var. citrata. A total of 14 samples of juice were prepared and two of them were used as controls and 12 samples were treated with medicinal plants. Total microbial count, coliforms, lactic acid bacteria and yeasts and microscopic fungi for testing the microbiological quality were detected. All the samples were negative for lactic acid bacteria. There were neither coliform bacteria nor yeast and fibrous microscopic fungi present in some of the treated samples apart from the control samples. Coliform bacteria of 1 log cfu/mL were detected during the first testing and identified Proteus vulgaris in the control sample of grape juice of the variety Welschriesling. The yeast of the genus Candida was present in 2 log cfu/mL and it was detected during first and second testing in the control sample of Cabernet Sauvignon, unlike the other samples. The sample of grape juice with the addition of sage had the most significant inhibitory effect on total count of bacteria. The most common microorganisms in all samples were Bacillus cereus and Acinetobacter johnsonii, however, those microorganisms were absent during second testing due to the action of naturally occurring antimicrobials in the grapes.

scholarly journals Effect of Lactobacillus rhamnosus on Physicochemical Properties of Fermented Plant-Based Raw Materials

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1182 ◽  
Author(s):  
Carmen Masiá ◽  
Poul Erik Jensen ◽  
Patrizia Buldo
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Physicochemical Properties ◽  
Food Industry ◽  
Raw Materials ◽  
Lactobacillus Rhamnosus ◽  
Titratable Acidity ◽  
Fermentation Time ◽  
Trained Panel ◽  
Volatile Organic

Texture and flavor are currently the main challenges in the development of plant-based dairy alternatives. To overcome them, the potential of microorganisms for fermentation of plant-based raw materials is generating great interest in the food industry. This study examines the effect of Lactobacillus rhamnosus, LGG® (LGG® is a trademark of Chr. Hansen A/S) on the physicochemical properties of fermented soy, oat, and coconut. LGG® was combined with different lactic acid bacteria (LAB) strains and Bifidobacterium, BB-12® (BB-12® is a trademark of Chr. Hansen A/S). Acidification, titratable acidity, and growth of LGG® and BB-12® were evaluated. Oscillation and flow tests were performed to analyze the rheological properties of fermented samples. Acids, carbohydrates, and volatile organic compounds in fermented samples were identified, and a sensory evaluation with a trained panel was conducted. LGG® reduced fermentation time in all three bases. LGG® and BB-12® grew in all fermented raw materials above 107 CFU/g. LGG® had no significant effect on rheological behavior of the samples. Acetoin levels increased and acetaldehyde content decreased in the presence of LGG® in all three bases. Diacetyl levels increased in fermented oat and coconut samples when LGG® was combined with YOFLEX® YF-L01 and NU-TRISH® BY-01 (YOFLEX® and NU-TRISH® are trademarks of Chr. Hansen A/S). In all fermented oat samples, LGG® significantly enhanced fermented flavor notes, such as sourness, lemon, and fruity taste, which in turn led to reduced perception of the attributes related to the base. In fermented coconut samples, gel firmness perception was significantly improved in the presence of LGG®. These findings suggest supplementation of LAB cultures with LGG® to improve fermentation time and sensory perception of fermented plant-based products.

scholarly journals Impact of Milk Fortification on the Microbiological and Physicochemical Properties of Set-Type Skimmed Yoghurt Using Three Commercial Soluble Prebiotics

Foods ◽  
2019 ◽  
Vol 8 (6) ◽  
pp. 181 ◽  
Author(s):  
Rui Li ◽  
Qi Ding ◽  
Xin-Huai Zhao
Keyword(s):  
Acetic Acid ◽  
Lactic Acid ◽  
Physicochemical Properties ◽  
Acid Content ◽  
Titratable Acidity ◽  
Lactobacillus Delbrueckii ◽  
Chemical Compositions ◽  
Acid Fermentation ◽  
Ph Values ◽  
The Impact

The impact of milk fortification on the microbiological and physicochemical properties of a set-type skimmed yoghurt using three commercial soluble prebiotics (inulin, iso-malto-oligosaccharides, and xylo-oligosaccharides) at either 3 or 5 g/kg was assessed. The three prebiotics had an insignificant impact on yoghurt fermentation because all yoghurt samples had similar titratable acidity and similar pH values after their lactic acid fermentation. Regarding the control yoghurt samples without prebiotics usage, the prebiotics-fortified yoghurt samples showed no difference in their main chemical compositions, hardness, syneresis extent, and apparent viscosity (p > 0.05), but had a slightly higher lactic acid content and a viable quantity of starter strains. All yoghurt samples had the same acetic acid content, while propionic and butyric acids were not produced. Yoghurt storage at 4 °C for 21 day gave these yoghurt samples decreased pH values and a viable quantity of starter strains (especially Lactobacillus delbrueckii subsp. bulgaricus) and unchanged acetic acid; however, it increased lactic acid contents. Overall, prebiotics fortification up to 5 g/kg had a completely insignificant impact on the fermentation and quality attributes of yoghurt samples but could possibly improve the health of consumers due to higher dietary fibers and starter strain populations.

The activity of thyme essential oil against Acinetobacter spp.

2011 ◽  
Vol 6 (3) ◽  
pp. 405-413 ◽  
Author(s):  
Monika Łysakowska ◽  
Andrzej Denys ◽  
Monika Sienkiewicz
Keyword(s):  
Essential Oil ◽  
Antimicrobial Properties ◽  
Diffusion Method ◽  
Thymus Vulgaris ◽  
Bacterial Strains ◽  
Acinetobacter Baumanii ◽  
Strong Activity ◽  
Thyme Essential Oil ◽  
Acinetobacter Spp ◽  
Multiresistant Strains

AbstractThe aim of this work was to investigate the antimicrobial properties of thyme essential oil against clinical multiresistant strains of Acinetobacter spp. The antibacterial activity of oil was tested against standard and clinical bacterial strains of Acinetobacter genus. The agar diffusion method was used to check the inhibition of microbial growth at various concentrations of the oil from Thymus vulgaris. Susceptibility testing to antibiotics and chemotherapeutics was prepared using the disc-diffusion method. Identification of bacterial strains was carried out with the Vitek system and confirmed by PCR for Acinetobacter baumanii gyrB gene. The results of experiments showed that the oil from T. vulgaris exhibited an extremely strong activity against all of the clinical strains of Acinetobacter. Thyme oil demonstrated a very good efficacy against multiresistant strains of tested bacteria. Essential oils seems to be an excellent alternative for synthetic preparations and that is reason for an extensive assessment of their antimicrobial activity.

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