Background: Fermented dairy products are known for their many positive effects on human health and are consumed worldwide. The supplementation of food with plant extracts as sources of valuable ...nutritional compounds has recently gained a lot of attention. Milk and fermented products are deficient in bioactive components such as phenolic compounds and iron. Moringa oleifera leaf extract is rich in vitamins, minerals (iron), polyphenols, flavonoids, tannins and proteins. Its addition to milk before fermentation might represent an excellent way to enrich fermented milk products. Methods: Yoghurts enriched with moringa extract (ME) (1, 3 and 4-%, v/v) were produced and compared to a control yoghurt without ME. In all samples, acidity, microbiological parameters, syneresis and water holding capacity, rheology parameters, total colour difference, mineral content, total phenols and antioxidant capacity (FRAP method) and sensory properties were determined. Results: The addition of ME to milk before fermentation resulted in a shorter fermentation time, lower yoghurt pH, increased growth of yoghurt bacteria, better rheological properties and an increased total phenols content as well as antioxidant capacity of yoghurts. Moreover, yoghurts with ME addition had a higher mineral content and gained a better sensory score when compared to the control sample.
Background: White brined cheese is one of the most frequently consumed cheeses that is accepted among a large group of consumers, which is largely related to its unique sensory properties, which are ...characterized by specific technological processes including ripening in the brine. Thus, white brined cheese contains a high amount of NaCl, and frequent consumption might lead to excessive sodium intake, which nowadays, presents a global problem. Consequently, food industries have developed reduced sodium products by substitutional salts. Furthermore, various studies have indicated that increased sodium intake via the diet can be associated with cardiovascular diseases, a risk of digestive system cancer, obesity, and other conditions. Calcium salts (citrate and lactate) are safe for human health and can be added to various foods according to the quantum satis rule. The present study aimed to partially replace NaCl with Ca-citrate and Ca-lactate in proportions of 25% and 50%. Additionally, the study presents the possibility of applying Artificial Neural Network (ANN) models for the prediction of some brine and cheese properties. Methods: White brined cheese with substitutional salts in brine (25% and 50% Ca-citrate and 25% and 50% Ca-lactate) were produced and compared to the control cheese ripened in conventionally applied NaCl brine. The acidity, total dissolved solids, salt amount, conductivity, color, and textural and sensory properties were determined over the 28 days of cold storage. Results: The substitution of NaCl with Ca-citrate and Ca-lactate is promising for sodium reduction in white brined cheese, whereby the physical and chemical properties remain acceptable. The best sensory score gain occurred with a substitution of 25% NaCl with Ca-citrate. Furthermore, ANN models can be employed to predict brine and cheese properties during storage.
This study investigated the potential of olive leaf extract (OLE), as a functional ingredient, to improve cheese properties, because it is rich in phenols. Milk and dairy products are poor in ...phenolic compounds. The main objective was to determine the most effective coagulation method and timing of OLE supplementation to maximize retention in the cheese matrix. Experimental cheeses were produced using the rennet and acid coagulation methods, with OLE added either directly to the cheese milk or to the curd phase. Three OLE effective concentrations corresponding to 25%, 50%, and 75% inhibition of DPPH reagent (EFC25, EFC50, and EFC75, respectively) were added, i.e., 11.5 mg GAE L
, 16.6 mg GAE L
, and 26.3 mg GAE L
, respectively. The results showed that OLE significantly increased the concentration of total phenols, total flavonoids, and antioxidant activity in all cheese samples and in the residual whey, especially at higher effective concentrations (EFC 50 and EFC 75). Rennet-coagulated cheese to which OLE was added prior to coagulation (EM 25, EM 50, EM 75) exhibited higher hardness, gumminess, and chewiness but lower elasticity, suggesting alterations in the paracasein matrix. OLE did not adversely affect acidity, water activity, or cheese yield. However, higher EFC resulted in significant colour changes (∆E* > 3.0). In conclusion, the enrichment of cheesemaking milk with OLE and the application of the rennet coagulation method are the most suitable to optimise the production of OLE-enriched cheese. This research shows the potential to improve the nutritional value of cheese while maintaining its desired characteristics.
Mare milk is known for therapeutic properties due to the presence of bioactive components that are sensitive to thermal treatments and tend to lose their activity. Accordingly, mare milk is consumed ...raw or frozen, but for food safety reasons recent studies suggest mandatory pasteurization of mare milk before consumption. The aim of this study was to examine the effects of different heat treatments on mare milk quality and compare those to heat induced changes in cow milk. In all milk samples, the total dissolved solids (TDS), electrical conductivity (EC), antioxidant capacity (AC) by the DPPH and FRAP methods, changes in colour (ΔE*), concentration of 5-hydroxymethylfurfural (HMF) and the total phenols (TPC) were determined. Heat induced protein denaturation was monitored by SDS-PAGE, while NIR was applied for qualitative analysis of structural changes. In-bottle sterilization at 116 °C/16ʹ and 120 °C/5ʹ showed to be inappropriate for mare milk processing, since they resulted in the most intense colour changes (ΔE*>5), the highest free and total HMF concentrations (40.70 μmol/L free, 70.26 μmol/L total HMF at 116 °C/16ʹ; 35.49 μmol/L free, 58.12 μmol/L total HMF at 120 °C/5ʹ) and the most intense protein denaturation. On contrary, the applied HTST regimes (72 °C/20”, 85 °C/30”, 90 °C/5ʹ) and thermisation at 63 °C/15” were appropriate for mare milk processing considering the studied qualitative changes. Thereby, the HMF concentration, FRAP, TPC and ΔE* value, combined with NIR analysis showed a good potential to be used as rapid and useful tools for monitoring the intensity of heat induced changes in mare milk.
The aim of this study was to determine how storage in the frozen state affects the quality of mare milk. Therefore, physicochemical properties such as pH, total dissolved solids (TDS), electrical ...conductivity (EC), particle size distribution and near-infrared (NIR) spectroscopy, as well as changes in antioxidant activity and the total phenol content were determined during 6 months of storage at -18°C. All of the determined parameters were compared to those in raw mare milk prior to freezing. According to the obtained results, frozen storage caused certain changes in mare milk quality, including increase in pH, electrical conductivity and TDS values, changes in protein structure recorded by NIR spectroscopy and SDS PAGE (Sodium dodecyl sulfate-polyacrylamide gel electrophoresis), as well as changes in particle size distribution. There was also a continuous decrease in the antioxidant activity and the total phenol content of frozen mare milk throughout the 6 months of frozen storage. Thus, after 6 months of frozen storage, a decrease in the DPPH value of approximately 59%, in the FRAP value of approximately 26% and in the TPC of approximately 70% was observed, respectively. In conclusion, freezing and frozen storage affected the quality of mare milk, which might have negative consequences on its therapeutic value.
Whey and buttermilk are the main by-products of the dairy industry, both having excellent nutritional properties. Buttermilk contains a unique component, the milk fat globule membrane (MFGM). MFGM ...contains bioactive compounds with positive health effects like antitumour or cholesterol-lowering impact. Whey proteins are found in whey and are a source of bioactive peptides acting positively on coronary, gastrointestinal, immune and nervous systems. Yet, buttermilk and whey are insufficiently utilized in functional food production. Various technological solutions have been studied in order to increase the production of foods based on whey and/or buttermilk whereby the production of beverages appear to be most acceptable from the economic and technological point +of view. Thus, the aim of this paper is to give an overview of current knowledge about the possibilities of creating whey and/or buttermilk beverages.
The use of ultrafiltration in whey processing is limited by reduced flux and separation originating from fouling. Since the processing conditions applied determine ultrafiltration performance, this ...study focused on investigating the influence of temperature (20 or 50 °C) and the pre-treatment applied (pasteurisation, cross-flow microfiltration) on the ultrafiltration of sweet whey using a 20 kDa ceramic membrane. The highest flux and the lowest total filtration resistance were recorded at 20 °C, with predominantly reversible fouling, most probably arising from protein deposition, while at 50 °C, calcium could have played an important role. Whey microfiltration using a 0.5 μm ceramic membrane enhanced ultrafiltration, giving significant flux increase and fouling reduction, while the obtained microbial reduction was almost equal to pasteurisation. Ultrafiltration of pasteurised whey at 50 °C proved to be least suitable, while ultrafiltration of fresh or microfiltered whey at 20 °C provided the most desirable conditions.
The aim of this paper is to determine nutritive, functional, microbiological and sensory properties of probiotic beverages produced from different volume ratios of cow's milk and soy beverage (25:75, ...50:50 and 75:25). Pure cow's milk and soy beverage served as control samples. Fermentation was performed at 43 °C by a combined culture consisting of the probiotic strain
La5 and yoghurt culture. Viable counts of La5 strain in the produced beverages ranged from 7.52 to 8.20 log CFU/mL, which is above the probiotic minimum (10
CFU/mL). Lactic acid was the most prevalent organic acid in all samples (660.1 to 1003.0 mg/100 mL). The fatty acid profiles of fermented beverages were as follows: the mass fraction of saturated fatty acids was 22.2-82.7%, of unsaturated fatty acids 22.3-77.8% and of polyunsaturated fatty acids 15.5-65.9%. The main soy sugars were transformed well (80% stachyose and 50% raffinose conversion) into lactic acid during fermentation. Functional probiotic beverages were successfully produced from different volume ratios of cow's milk and soy beverage by
La5 and yoghurt culture. Mixing cow's milk with soy beverage significantly improved the sensory properties of the product, especially its smell, taste and colour. The acceptability test showed good acceptance by potential consumers of all fermented beverage samples except for the sample made from 100% soy beverage. In the end, the obtained results represent a good basis for further optimisation of the ideal volume ratios of cow's milk and soy beverage for production of fermented beverages characterised by good viability of probiotic bacteria as well as by good functional, nutritive and sensory characteristics.
Fresh (acid coagulated) cheeses belong to a group of soft unripen cheeses which are very popular among consumers. However, owing to the specific composition and properties, these cheeses have a ...limited shelf life. The aim of this study was to investigate the effect of modified atmosphere packaging (MAP) onto fresh cheese and to compare it with the commonly used packaging under atmospheric air and vacuum. The produced fresh cheese was packed under normal atmosphere (air), vacuum and modified atmosphere of following composition: (1) 60%N
2
:40%CO
2
; (2) 70%N
2
:30%CO
2
. All cheese samples were cool stored for 18 days, whereby the sampling and analyses were conducted every 3 days. During the storage period, there was a continuous decrease in acidity (from 4.66 to 4.47), while the viable counts of the monitored microorganisms increased in the control sample. However, in samples packaged under vacuum and modified atmosphere a slighter decrease in acidity (no result under 4.50) and inhibited microbiological growth were detected. Scores of sensory evaluations were high for all samples (17.63–19.73), whereby the sample packed under MAP with ratio 70%CO
2
:30%N
2
obtained the best average score of 17.72 at the end of the 18-day storage period. Other analyses confirmed that vacuum and MAP prolong the shelf life of fresh cheese while preserving its physico-chemical and sensory characteristics.
In this study, operating conditions for the cross flow microfiltration (CFMF) of sweet whey were optimised. Filtrations were performed for 65 min at 20, 40 and 50 °C using ceramic membranes with ...different nominal pore sizes (0.1, 0.5 and 0.8 μm). Periodically, samples of whey retentate and permeate were taken and analysed for microbiological quality and physical and chemical properties. The best microbial reduction rates were achieved during filtration using a 0.1 μm membrane at 50 °C. The highest flux rates were achieved during filtration at 50 °C with all tested membranes. Fouling intensity was the lowest after filtration using a 0.5 μm membrane at 20 °C. According to all results obtained, the membrane with the nominal pore size of 0.5 μm appeared to be optimal for purposes of preserving the nutritional value, minimising membrane fouling and achieving appropriate microbiological quality of sweet whey.
PDF
