Studies on an inhibitor produced by lactic acid bacteria of wines on the control of malolactic fermentation

Malolactic fermentation is the microbiological process in wines, where lactic acid bacteria (LAB) govern the process of converting L-malic acid into L-lactic acid. During this process a high microbial load of LAB may lead to an unwanted spoilage phenomena by formation of excessive amounts of undesirable flavor compounds. This study is mainly focused on the isolation of LAB from the native flora of the wine, which has an inhibitory potential against malolactic activity of LAB inherent in wines. An isolate of Leuconostoc mesenteroides subsp. cremoris was found to produce an inhibitory compound against the LAB of wines. This compound was found to be a bacteriocin-like inhibitory substance (BLIS), which has a molecular weight of 32,000 Da, and it was shown that this BLIS was effective in the control of malolactic fermentation

Application of ultrasound and high-pressure homogenization against high temperature-short time in peach juice

The scope of current research was to investigate the impact of ultrasound (US) and high-pressure homogenization (HPH) on the quality of peach juice and to compare it with the effect of high temperature-short time (HTST) treatment. The quality parameters were monitored during 4 weeks. Compared with the HPH- and US-treated peach juices, HTST treatment increased the viscosity of peach juice. The enzyme inactivation (PPO and PME) in juice samples was improved significantly with an US. In addition, US and HPH treatments play a better role in ascorbic acid preservation in juices compared with the HTST treatment. Similarly, HTST-treated peach juices showed the lowest antioxidant capacity compared to the US- and HPH-treated juice samples during the storage. Finally, US-treated peach juices resulted in the highest phenolic content during the storage. In overall, both US and HPH treatments preserved the quality of peach juice remarkably compared with the HTST. Practical applications: An important enhancement in the quality retention of ultrasound (US)-treated juice compared to the high temperature-short time-treated peach juice was obtained. This work contributes a novel method to produce US-treated fresh fruit and vegetable juices with an improved product quality. In overall, processing of peach juice with an US treatment can be used to get a high-quality product as demonstrated by its quality retention ability during cold storage. © 2019 Wiley Periodicals, Inc

Online learners’ interactions and social anxiety: the social anxiety scale for e-learning environments (SASE)

2-s2.0-85086790220Social sharing in virtual learning environments differs from real environments, resulting in a need for a specialized data collection tool related to social anxiety in these environments. This study seeks to develop a scale to identify the levels of social anxiety experienced in e-learning. The study group consists of 275 students who have previously experienced an online or a blended learning environment. The data were analyzed through exploratory factor analysis, confirmatory factor analysis, convergent and divergent validity tests. The interpersonal interactions of learners in online environments were considered in developing the tool. Two subscale forms were created to identify the levels of social anxiety in learner-learner interaction and learner-instructor interaction. Each subscale of the Social Anxiety Scale for E-Learning Environments (SASE) consists of 23 items and three subfactors. These sub-factors are called negative evaluation, somatic symptoms and avoidance of interaction. The analyses indicate that the SASE is a reliable and valid measurement tool useful for assessing the social anxiety levels of online learners. © 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group

Online learners' navigational patterns based on data mining in terms of learning achievement

13th International Conference on Cognition and Exploratory Learning in Digital Age 2016, CELDA 2016 -- 28 October 2016 through 30 October 2016 -- -- 125287The aim of this study is to determine navigational patterns of university students in a learning management system (LMS). It also investigates whether online learners' navigational behaviors differ in terms of their academic achievement (pass, fail). The data for the study comes from 65 third grade students enrolled in online Computer Network and Communication lesson in a state university. As the online learning environment, Moodle, an open source software, is used in this study. Navigational log records derived from database were converted into sequential database format. According to students' achievement (pass, failure) at the end of the academic term, these data were divided in two tables. Page connections of the users were transformed into interaction themes namely, homepage, content, discussion, messaging, profile, assessment, feedback and ask the instructor. Data transformed to sequential patterns by the researchers were organized in navigational pattern graphics by taking frequency and ratio into consideration. To test the difference between obtained patterns ratio test was conducted by means of z statistics. The findings of the research revealed that first and second order navigational patterns of passed and failed students in the online learning environment had similar features, but passed students allocated more time to interaction process

Chemical, microbiological, and physical characteristics of commercial Swiss-type cheeses

WOS: 000270072200009High quality Swiss cheeses vary in sensory, chemical, microbiological, and physical characteristics. Determining the compositional characteristics of commercial Swiss cheeses will establish the typical range for each characteristic in cheeses intended for the American market and will complement descriptive sensory and consumer preference studies. The objective was to determine chemical, microbiological, and physical characteristics of commercial Swiss-type cheeses. Fifteen cheeses (4 US-manufactured baby Swiss, 10 US-manufactured Swiss, and one European Emmental) were analyzed for characteristics including protein, fat, moisture, salt, pH, short chain free fatty acids, and total free amino acids. Lactobacillus spp., Streptococcus thermophilus, and Propionibacterium spp. were enumerated. Physical characteristics such as hardness, springiness, and meltability were determined. The values for compositional characteristics were 23-26% for protein, 46-55% for fat in dry matter, 36-42% for moisture, and 0.7-3.4% for salt-in-moisture. The pH values ranged from 5.4 to 5.8, and the total free amino acid levels ranged from 23 to 105 mmol/kg. The bacterial counts varied widely (3-8 log CFU/g). Emmental cheese had the lowest meltability, and highest acetic and propionic acid levels

Association Between Early Idiopathic Neonatal Jaundice and Urinary Tract Infections

Background and purpose: Etiologic role, incidence, demographic, and response-to-treatment characteristics of urinary tract infection (UTI) among neonates, its relationship with significant neonatal hyperbilirubinemia, and abnormalities of the urinary system were studied in a prospective investigation in early (<= 10 days) idiopathic neonatal jaundice in which all other etiologic factors of neonatal hyperbilirubinemia were ruled out