1st International Electronic Conference on Food Science and Functional Foods

This research aimed to conduct a comparison of 8 different forms of brewery spent grain (BSG) on their polyphenolic content and antioxidant capacity as part of their potential as a functional food ingredient. The BSGs were dried until they reached a stable weight, grounded to pass through a 385 µm sieve and were vacuum packed in non-transparent packaging for further analysis. The results showed that BSG contained a high dietary fiber content which was dominated by a insoluble dietary fiber level of about 38.0–43.9% and a soluble dietary fiber content of about 3.9–9.6%. There were three groups of polyphenolic identified: flavan-3-ols, phenolic acids and flavonols at quantities of 362.1–1165.7 mg/kg, 65.8–122.5 mg/kg and 3.6–13.8 mg/kg, respectively. Antioxidant capacity was examined using an in vitro assessment: the 2,2′-Azinobis-(3-Ethylbenzthiazolin-6-Sulfonic Acid) (ABTS) capacity ranged from 0.086 to 0.241 mmol Trolox/100 g while the ferric reducing antioxidant potential (FRAP) capacity ranged from 0.106 to 0.306 µmol TE/100 g. In conclusion, BSG as a brewery waste can potentially be used as a functional food ingredient due to its properties. It is suggested that further studies are needed to explore BSG’s impact on the development of functional food products.Keywords: brewery spent grain; valorization; agricultural by-products; functional food; dietary fiber; polyphenolic compounds; antioxidant</p

Diversity and Stability of Lactic Acid Bacteria in Rye Sourdoughs of Four Bakeries with Different Propagation Parameters.

We identified the lactic acid bacteria within rye sourdoughs and starters from four bakeries with different propagation parameters and tracked their dynamics for between 5-28 months after renewal. Evaluation of bacterial communities was performed using plating, denaturing gradient gel electrophoresis, and pyrosequencing of 16S rRNA gene amplicons. Lactobacillus amylovorus and Lactobacillus frumenti or Lactobacillus helveticus, Lactobacillus pontis and Lactobacillus panis prevailed in sourdoughs propagated at higher temperature, while ambient temperature combined with a short fermentation cycle selected for Lactobacillus sanfranciscensis, Lactobacillus pontis, and Lactobacillus zymae or Lactobacillus helveticus, Lactobacillus pontis and Lactobacillus zymae. The ratio of species in bakeries employing room-temperature propagation displayed a seasonal dependence. Introduction of different and controlled propagation parameters at one bakery (higher fermentation temperature, reduced inoculum size, and extended fermentation time) resulted in stabilization of the microbial community with an increased proportion of L. helveticus and L. pontis. Despite these new propagation parameters no new species were detected

Evolution of Bacterial Consortia in Spontaneously Started Rye Sourdoughs during Two Months of Daily Propagation

<div><p>The evolution of bacterial consortia was studied in six semi-solid rye sourdoughs during long-term backslopping at different temperatures. Each rye sourdough was started spontaneously in a laboratory (dough yield 200), propagated at either 20°C or 30°C, and renewed daily at an inoculation rate of 1∶10 for 56 days. The changes in bacterial diversity over time were followed by both DGGE coupled with partial 16S rRNA gene sequencing and pyrosequencing of bar-coded 16S rRNA gene amplicons. Four species from the genus <i>Lactobacillus (brevis, crustorum, plantarum,</i> and <i>paralimentarius)</i> were detected in different combinations in all sourdoughs after 56 propagation cycles. Facultative heterofermentative lactic acid bacteria dominated in sourdoughs fermented at 30°C, while both obligate and facultative heterofermentative LAB were found to dominate in sourdoughs fermented at 20°C. After 56 propagation cycles, <i>Kazachstania unispora</i> (formerly <i>Saccharomyces unisporus</i>) was identified as the only yeast species that dominated in sourdoughs fermented at 20°C, while different combinations of strains from four yeast species (<i>Kazachstania unispora</i>, <i>Saccharomyces cerevisiae</i>, <i>Candida krusei</i> and <i>Candida glabrata)</i> were detected in sourdoughs propagated at 30°C. The evolution of bacterial communities in sourdoughs fermented at the same temperature did not follow the same time course and changes in the composition of dominant and subdominant bacterial communities occurred even after six weeks of backslopping.</p></div

Microbiological, chemical, and sensorial characterisation of commercially available plant-based yoghurt alternatives

Consumer demand for plant-based dairy alternatives has increased rapidly during the past few years and the market has been saturated with a wide variety of alternative products. The general aim of this study was to broaden the understanding of the composition and characteristics of currently commercially available plant-based yoghurt alternatives focusing especially on the content of live bacteria. The bacterial composition, including the content of live bacteria in yoghurt alternatives, was evaluated using metagenetic sequencing of the 16S rRNA gene amplicons in combination with the novel PMAxx treatment approach. The content of organic acids, sugars, and volatiles was measured, and descriptive sensory analysis was carried out to comprehensively describe the products. While the main ingredient (soya, oat, coconut, or lupin) determined the general characteristics of the product, significant differences were observed in both chemical and microbiological composition and sensorial attributes even among the yoghurt alternatives made from the same plant ingredient

Carbohydrate fermentation profiles of <i>Lactobacillus</i> species isolated on day 56 of sourdough backlopping.

<p>Carbohydrate fermentation profiles of <i>Lactobacillus</i> species isolated on day 56 of sourdough backlopping.</p

Ratio of species in the sourdoughs fermented at 20°C (20-I, 20-II, 20-III) or 30°C (30-I, 30-II, 30-III) after 56 backslopping cycles determined by plating on MRS and SDB media or by pyrosequencing of 16S rRNA gene amplicons.

<p>Ratio of species in the sourdoughs fermented at 20°C (20-I, 20-II, 20-III) or 30°C (30-I, 30-II, 30-III) after 56 backslopping cycles determined by plating on MRS and SDB media or by pyrosequencing of 16S rRNA gene amplicons.</p

Identification of DGGE bands obtained from six rye sourdoughs propagated at 20°C and 30°C during 56 days.

<p>Identification of DGGE bands obtained from six rye sourdoughs propagated at 20°C and 30°C during 56 days.</p

pH and total titratable acidity of six rye sourdoughs propagated at 20°C (20-I, 20-II and 20-III, shown in blue) and 30°C (30-I, 30-II and 30-III, shown in red) during 56 days.

<p>pH and total titratable acidity of six rye sourdoughs propagated at 20°C (20-I, 20-II and 20-III, shown in blue) and 30°C (30-I, 30-II and 30-III, shown in red) during 56 days.</p