Fermentation technology enables the better use of resources and the conversion of dairy waste into valuable food products. The aim of this study is to evaluate the conversion rate of glucose into fructose by immobilised glucose isomerase (GI) in sweet and acid whey permeates for glucose–galactose syrup production. The experiments demonstrated that the highest concentration of glucose and galacto-oligosaccharides (GOSs) in sweet and acid whey permeates was reached by GODO-YNL2 β-galactosidase, 32 ± 2% and 28 ± 1%, respectively. After glucose isomerisation, the highest fructose yield was 23 ± 0.3% and 13 ± 0.4% in sweet and acid whey permeates, where Ha-Lactase 5200 β-galactosidase was used for lactose hydrolysis in sweet and acid whey permeates. Finally, the results of this study highlight the potential for two-stage enzymatic hydrolysis to increase the sweetness of glucose–galactose syrup made from sweet and acid whey permeates.

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The aim of this study was to evaluate dehydrated sauerkraut juice (DSJ) in bread and meat applications and investigate bioaccessibility (BAC) of TPC in the analyzed products. In current research, sauerkraut juice, dehydrated sauerkraut juice, and bread and meat products prepared with dehydrated sauerkraut juice were analyzed. For all of the samples, total phenol content, antiradical activity by ABTS+, bioaccessibility, and volatile compound profile were determined. Additionally, sensory evaluation was performed to evaluate the degree of liking bread and meat with dehydrated sauerkraut juice. The addition of DSJ increased TPC in bread and meat samples. The bioaccessibility was higher for the control samples compared to DSJ samples. It exceeded 1 and is considered as good. DSJ did not promote bioaccessibility. Benzaldehyde was the highest peak area for the Bread DSJ and Meat DSJ samples, giving a roasted peanut and almond aroma. There were no significant differences in degree of liking for structure, taste, and aroma between the control bread and the Bread DSJ, while Meat DSJ was more preferable in sensory evaluation. DSJ could be used in food applications, but further research is necessary.

Barley (Hordium vulgare L.) grain is an important food ingredient due to the presence of essential compounds like β-glucans, proteins, resistant starch, phenolic compounds etc. β-glucans are able to lower cholesterol level in blood plasma and the glycaemic index, to enhance lipid metabolism and to reduce the risk of colon cancer. Hulless barley cultivars are more suitable to the human diet, because the hulls can be easily removed, as well as minimal grain processing in food production contributes to the full benefit of the whole grain. Several studies show that hulless grains have a higher digestible energy, and they have higher protein content compared to hulled grains. Different cultivars have unique composition and physical properties. The hulless barley cultivars are less studied than hulled barley and oats. The aim of this study was to evaluate the fermentation characteristics of flakes of different hulless barley cultivars in vitro and to analyse the fermentation pattern of β-glucans and proteins. Samples of six hulless barley cultivar flakes with different β-glucan (4.17–6.59%), soluble dietary fibre (18.1–32.0%) and resistant starch (0.74–10.65%) content were boiled in water 10 min, and the obtained porridge samples were treated under in vitro fementation conditions. The concentration of fermented porridge solids as well as β-glucans and proteins was measured. The concentration of undigested solids varied from 38.3 to 61.0% depending on barley cultivar. The concentration of protein was not significantly changed, but β-glucan concentration was significantly decreased after in vitro digestion comparing to indigestible samples.

The dairy industry is facing a problem associated with 1.6 billion tons of acid whey per year as a waste stream. The extended amount of acid whey has encouraged studies for novel approaches of acid whey utilization. The production of lactobionic acid (LBA) using dairy waste has been in rapid demand as an economically feasible and environmentally friendly approach. The composition of acid whey makes lactose conversion into LBA by Pseudomonas taetrolens complicated. Therefore, the aim of the current research was to evaluate factors (quality of whey (salts, protein concentration, pH), volume of inoculum, and cultivation time) with the purpose of increasing the suitability of acid whey for biotechnological LBA production. LBA production was performed in a 4L bioreactor, which was equipped with a pH electrode and a dissolved oxygen electrode. The whole experiment was performed at a temperature of 30 °C under 350 rpm agitation. The continuous aeration was set at 0.5 L/min. The current study presents the study of acid and sweet whey combinations in different ratios (100:0; 50:50; 60:40, 70:30, 80:20, respectively) inoculated with 10% or 30% v/v of fresh P. taetrolens inoculum reaching up to 59.9 ± 1% LBA yield during cultivation. Increasing protein and pH in a substrate slows down the lactose converting ability of P. taetrolens. Results demonstrated that increasing the acid whey amount in a substrate can affect the LBA yield, and a combination of sweet and acid whey could be a good solution for biotechnological LBA production using dairy waste. Doi: 10.28991/HEF-SP2022-01-04 Full Text: PDF