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consumers ( Maray et al., 2017 ; Nketia et al., 2020 ). Preservation of mushrooms by fermentation is also an affordable and efficient method domestically used in Eastern Europe and Asia ( Jabłońska-Ryś et al., 2016 ). The current study aims to investigate
. Scalabrini , P. , Rossi , M. , Spetolli , P. , Matteuzzi , D. : Characterization of Bifidobacterium strains for use in soymilk fermentation . Inter J Food Microb 39 , 213 – 219 ( 1998 ). 8
dried and crushed using in daily life. Recently, fermentation technology has been applied to the processing of trifoliate orange to reduce its bitterness and enhance its nutritional value and biological activities. However, the complex fermentation
The need to introduce promising bioethanol production technologies calls for advanced laboratory techniques to study experiment designs and to obtain their results in a quick and reliable way. Real time monitoring based on general principles of ethanol fermentation, such as effluent CO2 volume, avoids time consuming steps, long lasting analyses and delivers information about the process directly. A device based on the above features and capable for real time monitoring on parallel channels was developed by the authors and is described in this paper. Both for calibration and for fermentation, test runs were carried out on different days and channels. Statistical evaluation was based on the obtained data. According to the t-test (P=0.05) and Grubbs analysis, the calibration method is reliable regardless of the date of calibration. When evaluating the fermentation results by ANCOVA acceptable standard derivations were obtained as impact of channel (58.8 ml), date (82.1 ml) and incorporating all impacts (116.2 ml). The final ethanol concentrations calculated based on the gas volume were compared to ones determined by HPLC and an average difference of 10% was found. Thus, the device proved to be advantageous in monitoring fermentation.
In recent years, great interest has been dedicated to vegetable juices processed by lactic acid fermentation because they contain high amount of beneficial substances such as vitamins, mineral compounds, dietary fibre and anticancer compounds. Six types of vegetable juices were inoculated by Lactobacillus plantarum 92H and fermented at 22 °C during 150 h. On the basis of analytical (pH, total acidity, content of reducing sugars, organic acids and biogenic amines) and sensory test results (evaluation of colour, turbidity, appearance, odour and taste), cabbage and cabbage-carrot (2:1, v/v) juices were selected as the most suitable for consumers. We recommend stopping the fermentation of these juices after 72 and 96 h of fermentation.
Implementation of sourdough technology would increase nutritional value and attractiveness of gluten-free bread. However, fermentation process requires stimulation. The course of fermentation of gluten-free sourdoughs prepared from maize and soy flours and maize and potato starches, enriched in glucose and casein hydrolysate or soy sprouted seeds used as fermentation enhancers was evaluated. The clearest effect of the supplementation was observed in the case of sourdough prepared from starches only. The addition of glucose in the amounts as low as 0.5% has proved to be enough to enhance fermentation effectively. Supplementation of the sourdoughs with peptides was not very effective; however, when used together with glucose, a synergistic effect could be detected. The addition of sprouted seeds allowed to shorten the fermentation process with up to several hours. These studies have demonstrated possibility to simplify and shorten the process of gluten-free sourdough fermentation by modification of mixtures composition.
Changes in microbial population, pH, sugar, organic acid, anthocyanins, total soluble phenolics, and anti-glucosidase contents were measured during fermentation of mulberry juice at 30 °C by probiotic Leuconostoc mesenteroides showing rapid growth after an approximately 1-day lag phase and reaching a maximum of 8.6 log CFU ml−1 after 4 d. During the rapid growth phase, the main mulberry juice sugars, glucose and fructose, were largely consumed, and the acidic metabolites, lactic acid and acetic acid, were produced accordingly. A slow decrease in the concentration of the main organic acid, citric acid, was also observed during fermentation. After 4 d fermentation, anthocyanin content showed a 44.4% reduction, but the total amount of soluble phenolics and α-glucosidase inhibitory activity showed no significant changes (P>0.05). This suggests that L. mesenteroides fermentation of mulberry juice is a good strategy to enhance its probiotic value and to decrease the sugar content without changing the anti-glucosidase activity, which is required to reduce postprandial rise in blood glucose.
The primary purpose of these researches was to optimize single-cell protein (SCP) production process using Saccharomyces cerevisiae NCAIM Y.00200 and Kluyveromyces marxianus DSM 4908 strain, and then to analyse the changes in yield of single-cell protein final product using vitamin supplementation. To determine these values, the total sugar content of the fermentation medium, and the protein content of the yeast was determined. During our work, a particular attention was paid to the change of sugar content and yeast protein quantity. Besides, yield (Yx/s) values, typical of the whole fermentation, were also measured. Protein yield, as the final product of fermentation, featured the efficiency of our work. The results of our optimized trial settings that were considered as control, using S. cerevisiae NCAIM Y.00200 and K. marxianus DSM 4908 strains, were compared with the results of vitamin-supplemented fermentation processes. On this basis, we can say that during our trials vitamin supplementation did not influence the final product yield of processes. The counted protein yields during fermentation were between 0.4–0.7 g g−1.
Phytase is an important feed and food additive, which is used in diets to increase the absorption of divalent ions, amino acids, and proteins in the bodies and to decrease the excessive phosphorus release in the manure to prevent negative effects on the environment. To date, phytase has been mostly produced in solid state fermentations with insignificant production volumes. Thus, there is a need to produce phytase in submerged fermentations, which can be scaled-up for commercial productions. Additionally, optimization of fermentation medium has not been studied well in the literature. Therefore, this study has been undertaken to improve Aspergillus ficuum phytase production in submerged fermentations by optimizing important nutrients in the fermentation medium (glucose, Na-phytate, and CaSO4) using Box-Behnken design of Response Surface Methodology. Also, effects of pH and temperature on phytase activity were studied. Optimum glucose, Na-phytate, and CaSO4 concentrations were determined as 126, 14, and 1.1 g l–1, respectively. Additionally, pH 5.5 and 55 ºC were determined as optimum for the produced A. ficuum phytase activity. Under these conditions, phytase activity was increased to 3.45 U ml–1, which is about 50% higher than the previous results. Furthermore, the lowest activity loss was observed under 4 ºC storage conditions during 1 week of storage.
Soymilk supplemented with 2% sucrose was inoculated with a mixture of Streptococcus thermophilus, Bifidobacterium lactis and Lactobacillus acidophilus. The fermentation was monitored by pH as a function of time. This sample was used as a basis for the formulation of beverages flavoured with pineapple, strawberry, coconut, kiwi, guava and hazelnut. The beverages were submitted to a sensory acceptance test with consumers using the nine-point structured hedonic scale. ANOVA and Preference Mapping were used to analyse data and results showed higher significant (P<0.05) acceptance for pineapple and guava flavours. The strawberry, kiwi and coconut flavours obtained acceptance close to 6.0 (liked slightly), while the hazelnut flavour was rejected (acceptance less than 5.0). This study demonstrated that it is possible to formulate highly acceptable soymilk beverages by way of lactic fermentation and addition of flavourings.
