Guava flavored whey-beverage processed by cold plasma: Physical characteristics, thermal behavior and microstructure.

The present study aimed to compare the physicochemical (pH), physical (rheology parameters and particle size), microstructure (optical microscopy) and thermal properties (differential scanning calorimetry) of guava flavored whey-beverages submitted to cold plama technology in different processing time (5, 10, and 15 min) and gas flow (10, 20, and 30 mL min-1) conditions with a conventional pasteurized product. Whey beverages treated by cold plasma presented higher pH values, lower consistency and lower viscosity, and a flow behavior index similar to Newtonian fluids. Milder cold plasma conditions resulted in whey beverages with higher pH, lower viscosity and consistency, and similar particle distribution and microstructure compared to the pasteurized product. In contrast, more severe processing conditions resulted in a higher particle surface area ([D 3,2]) and smaller particles (~10 µM), due to the decrease in the number of larger particles (1000 µM), cell rupture, the formation of cell fragments, and higher viscosity and consistency. The treatments did not affect the thermal properties (enthalpy and bound water) of any sample.

Effect of high-intensity ultrasound on the nutritional profile and volatile compounds of a prebiotic soursop whey beverage.

This study evaluated the nutritional profile and volatile compounds present in a novel prebiotic (inulin) soursop whey beverage, due to the effects of high-intensity ultrasound (HIUS). The prebiotic soursop whey beverage was produced and processed by non-thermal high-intensity ultrasound varying the power (0, 200, 400 and 600 W) and by high-temperature short time (72 °C for 15 s) thermal treatment. Total acidity, pH, ascorbic acid content, total phenolics compounds content, antioxidant activity, hypertensive activity, fatty acid profile, volatile organic compounds, macro and micro minerals, as well as the heavy metals in these products, were analyzed. Overall, the HIUS technology induced some positive changes in the nutritional profile of the soursop whey beverage including beneficial effects, e.g., increase of phenolic content, improvement of the antioxidant and anti-hypertensive activity and reduction of undesired minerals. Although some negative changes, such as degradation of the ascorbic acid, decrease of some minerals and production of certain volatile compounds were found, the beneficial effects were prominent, thus, opening new opportunities to develop healthy functional beverages.

Guava-flavored whey beverage processed by cold plasma technology: Bioactive compounds, fatty acid profile and volatile compounds.

The effect of cold plasma processing time and gas flow on bioactive compounds such as vitamin C, carotenoids and phenolic compounds, DPPH, angiotensin-converting-enzyme (ACE) inhibitory activity, fatty acids profile, and volatile compounds of guava-flavored whey beverage was investigated. For comparative purposes, a pasteurized beverage was also manufactured. Cold plasma increased the concentration of bioactive and volatile compounds, and proportionated changes in the fatty acids profile. The milder conditions like lower flow rate and processing time, resulted in higher vitamin C and volatile compounds levels, and higher antioxidant activity, but with a lower carotenoids content and a less favorable fatty acids profile. More drastic conditions like higher flow rate and processing time resulted in products with lower vitamin C and volatile compounds levels, but with higher carotenoids content and ACE inhibitory activity. It can be concluded that the cold plasma processing can improve the properties of the guava-flavored whey beverages (increased concentration of bioactive and volatile compounds), while the effect on the fatty acid profile and ACE inhibitory activity is dependent on the process parameters (processing time and flow rate).

Processing chocolate milk drink by low-pressure cold plasma technology.

This study aimed to evaluate the effect of the process time (5, 10, and 15 min) and flow rate (10, 20, and 30 mL/min) of cold plasma technology on physio-chemical characteristics (pH), bioactive compounds (DPPD, Total Phenolic Compounds, ACE-inhibitory activity values), fatty acid composition, and volatile compounds profile of chocolate milk drink. The mild (lower flow rate and process time) and more severe (higher flow rate and process time) conditions led to a reduction of the bioactive compounds (total phenolic compounds and ACE-inhibitory activity), changes in fatty acid composition (increased saturated fatty acid and decreased monounsaturated fatty acid and polyunsaturated fatty acid), less favorable health indices (higher atherogenic, thrombogenic and hypercholesterolemic saturated fatty acids and lower desired fatty acids), and lower number of volatile compounds. In contrast, in intermediate cold plasma conditions, an adequate concentration of bioactive compounds, fatty acid composition, and health indices, and increased number of volatile compounds (ketones, esters, and lactones) were observed. Overall, cold plasma technology has proven to be an interesting alternative to chocolate milk drinks, being of paramount importance the study of the cold plasma process parameters.

Microwave Processing: Current Background and Effects on the Physicochemical and Microbiological Aspects of Dairy Products.

Overheating is still a major problem in the use of conventional heating for milk and various dairy products, because it leads to the lowering of quality and sensory and nutritional values. Microwave (MW) heating has been credited with providing superior-quality dairy-based products with extended shelf-life, representing a good alternative to conventional heat treatment. The main drawback of MW heating refers to nonuniform temperature distribution, resulting in hot and cold spots mainly in solid and semisolid products; however, MW heating has been shown to be suitable for liquid foods, especially in a continuous fluid system. This review aims to describe the main factors and parameters necessary for the application of MW heating technology for dairy processing, considering the theoretical fundamentals and its effects on quality and safety aspects of milk and dairy products. MW heating has demonstrated great ability for the destruction of pathogenic/spoilage microorganisms and their spores, and also inactivation of enzymes, thereby preserving fresh characteristics of dairy products.

Whey acerola-flavoured drink submitted Ohmic Heating: Bioactive compounds, antioxidant capacity, thermal behavior, water mobility, fatty acid profile and volatile compounds.

Whey acerola-flavoured drink was subjected to Ohmic Heating (OH) under different operational conditions (45, 60, 80 V at 60 Hz and 10, 100, 1000 Hz with 25 V, 65 °C/30 min) and conventional pasteurization (65 °C/30 min). Bioactive compounds (total phenolics, DPPH, FRAP, ACE levels), fatty acid profile, volatile compounds (CG-MS), thermal behaviors (DSC) and water mobility (TD-NMR) were performed. Reduction of frequency (1000-10 Hz) resulted in a lower bioactive compounds and antioxidant capacity of the samples, except for the DPPH values. Concerning the thermal behaviors, fatty acids profile and volatile compounds, different findings were observed as a function of the parameters used (voltage and frequency). In respect of TD-NMR parameters, OH led to a slightly reduction of the relaxation time when compared to the conventional treatment, suggesting more viscous beverages. Overall, OH may be interesting option to whey acerola-flavoured drink processing.

Brazilian cheeses: A survey covering physicochemical characteristics, mineral content, fatty acid profile and volatile compounds.

Chemical characteristics, mineral levels (Ca, Fe, K, Mg, Na, Zn, Cr, Cu, and Mn), fatty acid profile and volatile compounds of typically Brazilian cheeses (Minas Frescal, Minas Padrão, Prato and Coalho, n = 200, equally distributed) were investigated. The cheeses have proven to be a source of Ca, Cu and Zn (>15% RDI/30 g), with low atherogenic and thrombogenic indices, with ethanol as the main alcohol and butanoic acid as the main acid, and moderate to high sodium content. Minas Frescal cheese presented lower nutritional value (proteins, lipids, and minerals), while Prato cheese had a higher fatty acids concentration, including conjugated linoleic acid (0.013 g 100 g-1). Coalho cheese had a higher acetic acid level, while citric acid and lactic acid predominated in Minas Padrão cheese. The results provide essential information for Brazilian consumers, demonstrated that the manufacturing conditions are heterogeneous and suggested that a standardized manufacturing protocol for dairy processors is needed.

Ohmic Heating: A potential technology for sweet whey processing.

The use of Ohmic Heating (OH) for sweet whey processing was investigated in this study. Whey samples were subjected to both different OH parameters (2, 4, 5, 7 and 9 V·cm-1 at 60 Hz, up to 72-75 °C/15 s) and conventional processing (72-75 °C/15 s). Physicochemical analyses (pH), color measurements (L*, a*, b*), rheological properties (flow curves and particle size distribution), microstructure (optical microscopy), bioactive compounds (ACE and antioxidant capacity), microbiological characterization (mesophilic bacteria, total coliforms, and thermotolerant coliforms), water mobility (TD-magnetic resonance domain), and sensory evaluation (descriptive analysis) were carried out. The OH effects on sweet whey characteristics depended on the applied electric field intensity. Higher saturation, higher color variation (ΔE*), and higher luminosity (L*) were observed in low electric fields. For bioactive compounds, the increase of the electric field negatively affected the preservation of the antioxidant capacity and the ACE Inhibitory Activity of bioactive peptides. OH and conventional samples exhibited a pseudo-plastic behavior (n < 1). OH performed at 4 and 5 V·cm-1 was able to provide similar levels of sensory profile and higher volatile compounds levels. The results suggested the OH technology as an interesting alternative to whey processing.

The xylooligosaccharide addition and sodium reduction in requeijão cremoso processed cheese.

The addition of xylooligosaccharide (XOS), sodium reduction and flavor enhancers (arginine and yeast extract) on the manufacture of requeijão cremoso processed cheese was investigated. The addition of XOS resulted in a denser and compact structure, with increased apparent viscosity, elasticity (G') and firmness (G*). The addition of XOS and yeast extract improved the rheological and physicochemical properties (decrease in viscosity and particle size and increase in melting rate) and sensory characteristics (improvement in salty and acid taste, greater homogeneity, and lower bitter taste). In addition, a positive effect of arginine was observed in the sensory characteristics of the requeijão cremoso processed cheese, but without improvements in the physicochemical and rheological characteristics. Overall, the XOS addition and sodium reduction proportionated the development of a healthier processed cheese formulation.

Chemical, sensory, and functional properties of whey-based popsicles manufactured with watermelon juice concentrated at different temperatures.

The effects of the concentration of watermelon juice at different temperatures (45, 55, or 65 °C) on the physicochemical and sensory characteristics, antioxidant capacity, and volatile organic compounds (VOCs) of whey-based popsicles were investigated. Total phenolic content, lycopene, citrulline, VOCs, melting rate, instrumental colour, antioxidant capacity, and the sensory characteristics (hedonic test and free listing) were determined. The temperature led to a significant decrease in bioactive compounds (total phenolics, lycopene, and citrulline). The popsicle manufactured with reconstituted watermelon juice concentrated to 60 °Brix at 65 °C presented higher antioxidant capacity and was characterized by the presence of alcohols, aldehydes and ketones and presented a similar acceptance to the untreated popsicle (except for flavour). It is possible to combine whey and concentrated watermelon juice for the manufacture of bioactive-rich popsicles, using the concentration temperature of 65 °C as a suitable processing condition for potential industrial applications.

Effects of ultrasound energy density on the non-thermal pasteurization of chocolate milk beverage.

This study presents the emerging high-intensity ultrasound (HIUS) processing as a non-thermal alternative to high-temperature short-time pasteurization (HTST). Chocolate milk beverage (CMB) was subjected to different ultrasound energy densities (0.3-3.0 kJ/cm3), as compared to HTST pasteurization (72 °C/15 s) aimed to verify the effect of the HIUS processing on the microbiological and physicochemical characteristics of the beverage. The application of HIUS at an energy density of 3.0 kJ/cm3 was able to reduce 3.56 ±â€¯0.02 logarithmic cycles in the total aerobic counts. In addition, the ultrasound energy density affected the physical properties of the beverage as the size distribution of fat globule and rheological behavior, as well as the chemical properties such as antioxidant activity, ACE inhibitory activity, fatty acid profile, and volatile profile. In general, the different energetic densities used as a non-thermal method of pasteurization of CMB were more effective when compared to the conventional pasteurization by HTST, since they improved the microbiological and physicochemical quality, besides preserving the bioactive compounds and the nutritional quality of the product.

The addition of inulin and Lactobacillus casei 01 in sheep milk ice cream.

The effect of the Lactobacillus casei 01 and inulin addition on sheep milk ice cream during storage (-18 °C, 150 days) was investigated. Control, probiotic and synbiotic ice cream (10% w/w sheep milk cream; 10% w/w sheep milk cream, L. casei 01, 6 log CFU/mL; 10% w/w inulin, L. casei 01, 6 log CFU/mL, respectively) were manufactured. Microbiological counts (probiotic count, survival after in vitro gastrointestinal resistance, Caco-2 cell adhesion), bioactivity and microstructure were analysed. Physical and textural characteristics, colour parameters, thermal analysis and organic acids/volatile compounds were also evaluated. All formulations supported L. casei 01 viability and maintained above the minimum therapeutic level (>6 log CFU/mL) during storage. Inulin did not affect L. casei 01 survival after the passage through simulated gastrointestinal tract and adhesion to Caco-2 cells while improved the ACE-inhibitory and antioxidant activity. L. casei 01 addition produced several volatile compounds, such as carboxylic acids, alcohols, aldehydes and ketones. Also, scanning electron microscopy showed an interaction between probiotic bacteria and inulin fibre on synbiotic ice cream and the adhesion of L. casei to Caco-2 cells was observed.

Partial substitution of NaCl by KCl and addition of flavor enhancers on probiotic Prato cheese: A study covering manufacturing, ripening and storage time.

Cheese is a suitable matrix to deliver probiotic strains but it contains a high amount of sodium. The effect of partial substitution of NaCl by KCl and the addition of flavor enhancers (l-arginine, yeast and oregano extract) on probiotic Prato cheese was investigated after 1, 30, and 60 d of refrigerated storage (immediately after manufacturing, and during ripening and storage). Microbiological (lactic acid bacteria and probiotic Lactobacillus casei 01 counts and survival under gastrointestinal conditions), physicochemical (pH, proteolysis, fatty acids), bioactivity (antioxidant effect and angiotensin I-converting enzyme inhibitory activity), rheological, and water mobility by means of time domain low-field nuclear magnetic resonance were investigated. Significant changes in probiotic survival were observed; however, the sodium reduction and the addition of flavor enhancers did not constitute an obstacle to L. casei 01 (>108 CFU/g) during storage. Slight changes were observed in proteolysis, bioactivity, water mobility, texture profile, and fatty acids of the cheeses as a function of the flavor enhancer added. The sodium reduction and the supplementation of Prato cheese with probiotic cultures may be an effective alternative to the production of a potentially functional cheese.

Whey-grape juice drink processed by supercritical carbon dioxide technology: Physicochemical characteristics, bioactive compounds and volatile profile.

The effect of supercritical carbon dioxide technology (SCCD, 14, 16, and 18MPa at 35±2°C for 10min) on whey-grape juice drink characteristics was investigated. Physicochemical characterization (pH, titratable acidity, total soluble solids), bioactive compounds (phenolic compounds, anthocyanin, DPPH and ACE activity) and the volatile compounds were performed. Absence of differences were found among treatments for pH, titratable acidity, soluble solids, total anthocyanin and DPPH activity (p-value>0.05). A direct relationship between SCCD pressure and ACE inhibitory activity was observed, with 34.63, 38.75, and 44.31% (14, 16, and 18MPa, respectively). Regards the volatile compounds, it was noted few differences except by the presence of ketones. The findings confirm the SCCD processing as a potential promising technology to the conventional thermal treatment.