Dairy By-products Research Articles

Development of Whey with Apple Juice and Appraisal of their Nutritional Qualities

This study was conducted at the Department of Food Science and Nutrition, Banasthali Vidyapith, Newai, Tonk, Rajasthan, India in 2006. A dairy by-product can be used to enrich fruit juices to enhance their therapeutic and nutritional value. This study was carried out to develop beverages using apple juice and incorporating whey at various percentage level and to conduct nutritional analysis. Protein value was varied between 0.72–1.9. Fat content was 0.50–1.10. The ascorbic acid level in the juices ranged between 2.97–0.85 and it was found to be decreasing with an increasing amount of whey. Acidity ranged was 0.20–0.34, it was increasing with the increasing amount of whey. Ash content level was also increased, the range was 0.20–1.50.

Proteomics analysis of milk fat globule membrane enriched materials derived from by-products during different stages of milk-fat processing

By-products produced during milk-fat processing contain abundant milk fat globule membrane (MFGM) and are usually considered as sources of MFGM proteins. However, the technological conditions during cream processing affect the composition/profile of the MFGM proteins and change the functional properties of MFGM proteins. In this paper, the simulative process of industrial manufacture of cream, butter and anhydrous milk fat was done in the lab, five kinds of by-products were collected from different stages (different technical treatments or different fat content) to isolate MFGM enriched material. Proteomics analysis of MFGM enriched materials was performed by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). 357, 429, 323, 578 and 332 proteins were identified in five groups of by-products. Several major MFGM proteins were detected in all samples with the high relative abundance. Samples obtained after phase inversion showed higher protein number and higher concentration of major MFGM proteins compared with centrifuged skimmed milk. Both the number and the concentration in samples collected after phase inversion increased with fat content of cream. GO analysis revealed GTPase activity was the specific molecular function of MFGM proteins in butter serum (BS-1). The MFGM protein profiles also provided novel insights into the individual MFGM product which was rich in certain membrane proteins. Butter serum was the best source for isolating complete MFGM proteins product. This work will facilitate the development of deep processing market for dairy by-products, and provide theoretical reference for the production of MFGM protein products.

Extraction of Dairy Phospholipids Using Switchable Solvents: A Feasibility Study.

A tertiary amine (N,N-dimethylcyclohexylamine, CyNMe2) was used as a switchable hydrophilicity solvent (SHS) for extracting phospholipids (PLs) from raw cream (RC), buttermilk (BM), concentrated buttermilk (CBM), and beta-serum (BS). The SHS extractions were performed with varying solvent–sample weight ratio at room temperature. The extracted PLs using CyNMe2 were recovered by bubbling CO2 at atmospheric pressure, switching the CyNMe2 into its respective salt. For comparison, the PLs were also extracted using Folch (FE) and Mojonnier (ME) extraction. The extraction efficiency of SHS varied from 0.33% to 99%, depending on the type of byproduct. The SHS extracted up to 99% of the PLs directly from BM, while only 11.37% ± 0.57% and 2.66% ± 0.56% of the PLs were extracted with FE and ME, respectively. These results demonstrate the applicability of SHS for the extraction of PLs from dairy byproducts.

Valorisation of Dairy Wastes Through Kefir Grain Production

The main aim of this work was to investigate on kefir grains (KGs) increase using different dairy by-products. To this purpose, whey and deproteinized whey from cow, goat and sheep milk were compared to the pasteurized milk of the corresponding animal species. Each substrate was inoculated with 3% (w/v) of KGs cultivated in ultra-high temperature cow milk and evaluated for pH decrease, total titratable acidity increase and development of lactic acid bacteria (LAB) and yeasts released in the matrices after 24 h incubation at three different temperatures (20, 25 and 30 °C). The genotypic characterization of the dominating microbial populations resulted in the identification of two LAB belonging to the species Lactococcus lactis and Leuconostoc mesenteroides and one yeast strain within the species Kluyveromyces marxianus. Among whey based fermentation media deproteinized sheep whey allowed the highest KGs increase (almost 50%). Results of the present investigations reveal the potential of the dairy wastes for KGs production at industrial level.

Electrical Processing of Whey. Role of Construction, Technological and Energy Characteristics of Reactors

The purpose of this work was to study the basic construction, energy, and technological features of the electrochemical reactors used in the manufacture of whey, a dairy by-product and a biologically very valuable liquid. The choice of optimal regimes for processing various types of whey was specified aimed at increasing the efficiency of the recovery of whey protein fractions in the protein-mineral concentrates through reduction of the energy consumption. It is demonstrated that features of the electric reactors must be reasonably selected, including the distances between the electrodes and between the electrodes and the membrane, as well as their geometric shape, to avoid occurrence of dead areas and to ensure a high efficiency of the process. It was also important to find the most appropriate options for electric parameters and processing regimes (periodic or continuous). In addition, the ratio of the whey volume and the main electrode area, the type of the regimes membrane, the initial content of the dry matter in each type of the whey (in particular, its protein composition), and the compositions and concentration of the anodic (secondary) liquid, were taken into account. The results of the study are significant for the development of a wasteless technology of processing the dairy by-products.

Leveraging endogenous barley enzymes to turn lactose-containing dairy by-products into fermentable adjuncts for Saccharomyces cerevisiae-based ethanol fermentations

Acid whey, a by-product of strained yogurt production, represents a disposal challenge for the dairy industry. Utilization schemes are currently limited; however, acid whey contains valuable components that could be used to create value-added products. One potential scheme would be the fermentation of acid whey into an alcoholic beverage. Sour beers are gaining popularity and acid whey, which is sour to begin with, could provide a new product opportunity. However, the main sugar of acid whey, lactose, cannot be fermented by the traditional brewer's yeast, Saccharomyces cerevisiae. It has been reported that barley contains enzymes capable of hydrolyzing lactose to glucose and galactose, which are fermentable by S. cerevisiae. We investigated whether a barley-based mash resulted in detectable hydrolysis of lactose into sugars fermentable by S. cerevisiae. We demonstrated the ability to hydrolyze lactose in acid whey using a barley-based mash, resulting in the average release of 3.70 g/L of glucose. Additionally, the subsequent liquid was fermented by S. cerevisiae to an average ethanol concentration of 3.23% alcohol by volume. This work demonstrates the ability to hydrolyze the lactose in acid whey using barley and the opportunity to use acid whey as a fermentable sugar source in beer production.

Whey prefermented with beneficial microbes modulates immune response and lowers responsiveness to milk allergens in mouse model

Whey is a rich dairy by-product emerging mostly during cheese production, with valuable nutritional, functional and bioactive properties and reduced immunogenicity of the protein fractions. The aim of the study was to evaluate therapeutic potential and immunoreactivity with milk antigens of whey prefermented with potentially probiotic bacteria (with Streptococcus salivarius subsp. thermophilus 2 K and Lactobacillus delbrueckii subsp. bulgaricus BK – FW whey, or with S. thermophilus 2 K, L. bulgaricus BK, Lactobacillus plantarum W42, and Bifidobacterium animalis ssp. lactis Bi30 – FW-LB whey). The study was conducted on a mice model with induced cow’s milk proteins allergy (CMPA). Interventional feeding of α-CN + β-LG immunized mice with FW and FW-LB whey changed Th1/Th2 balance towards a Th1 response and enhanced the secretion of regulatory cytokines, and reduced allergy markers level. The presence of L. plantarum W42 and B. lactis Bi30 significantly enhanced the observed therapeutic effect of whey prefermented with yogurt cultures.

CHARACTERIZATION OF COLLAGEN DERIVED PRODUCTS PREPARED BY USE OF ALKALI AND DAIRY BY-PRODUCT

Leather processing is one of the highly polluting industries, due to generation of significant quantities of tanned and untanned wastes. Untanned wastes are less contaminated with chemicals and a better source of high value products such as collagen rather than tanned or finished leather wastes. In the present study, collagen dissolution substances (CDS) were prepared from bovine limed split wastes as value added products, by treating leather wastes with sodium hydroxide and fermented dairy by-product. After dissolution processes, the samples were lyophilized and their morphologies were examined with table top scanning electron microscopy (TSEM). The structures of CDS were characterized by X-Ray Diffraction (XRD), differential scanning calorimeter (DSC), and Fourier Transform Infrared Spectrometer (FTIR). In addition to the organoleptic evaluation of CDS, total Kjeldahl nitrogen and fat content, distribution of fatty acid methyl esters and spectrophotometric color determination of CDS were also investigated. The characteristics of CDS revealed that the alkali treatment caused a high degree of dissolution and led to deformation of the collagen structure. In comparison to alkali dissolution, CDS obtained with fermented dairy by product were found to have acceptable chemical and colloidal properties due to the conservation of collagen polypeptide bond structure. Following the results obtained, it may be concluded that fermented dairy by-product may find use for the hydrolyzation of collagen.

Application of Transglutaminase Crosslinked Whey Protein–Pectin Coating Improves Egg Quality and Minimizes the Breakage and Porosity of Eggshells

It is well known that an effective way to improve the quality attributes of food is the use of coatings. Moreover, there is evidence of the use of dairy byproducts to design coatings to improve the shelf life of food products. This study was conducted to explore the effectiveness of a film forming solution containing whey protein–pectin complex enzymatically reticulated by transglutaminase (TGase) applied as a coating on eggshells to preserve the internal quality of eggs stored under environmental conditions (25 ± 1 °C and 35% HR) during 15 days storage. Eggs properties tested included yolk index, albumen and yolk pH, albumen CO2 content, water loss, shell strength, and microbial permeability through the shell. The results showed that the coating maintained a higher yolk index and albumen carbon dioxide content, reduced the weight loss and increased both albumen and yolk pH values with respect to the uncoated eggs. All coated eggshells showed greater strength than those of uncoated eggs. Moreover, by using Blue Lake dye penetration method we demonstrated that the coating reduced the Blue Lake dye penetration confirming the effectiveness of the coating on the reduction of post-wash bacterial penetration. These results suggest that the studied coating can be useful to preserve internal egg quality but also to reduce the breakage of eggshell and egg microbial contamination. Based on this result we can conclude that the coating made with whey protein–pectin crosslinked by TGase could be an effective strategy to increase the shelf life of eggs preserved in environmental conditions and to reduce economic losses due to the eggs breakage during their marketing.

Extraction of phospholipids from a dairy by-product (whey protein phospholipid concentrate) using ethanol

There has been a great interest in the phospholipids (PL) found in dairy products because of their health and functional properties. In this study, a technology that was originally developed for egg yolk PL extraction was applied to whey protein phospholipid concentrate (WPPC). This method successfully precipitated the proteins present in WPPC and extracted the lipids with a renewable alcoholic solvent, ethanol. The effect of ethanol concentration, extraction temperature, and extraction number on the recovery of total lipid, total PL, and individual PL class was evaluated. The optimum processing conditions for a combined 5-stage sequential extraction for producing a PL-enriched lipid fraction were determined to be 70% ethanol at 70°C, and the total lipid recovery, total PL recovery, and PL content achieved were 40.7, 58.1, and 45.8%, respectively. A lipid fraction with high nutritional value (high content of sphingomyelin or phosphatidylserine) can also be obtained by adjusting extraction conditions and collecting specific fractions, although the yield may decrease. Overall, producing a PL-rich lipid fraction from WPPC using ethanol extraction is feasible and scalable, and different processing conditions can be used depending on the type of lipid product desired.

Effect of high pressure treatment on the antirotaviral activity of bovine and ovine dairy by-products and bioactive milk proteins

Abstract Whey and buttermilk have shown a certain degree of neutralizing activity against rotavirus, which are still a serious public health problem worldwide. High hydrostatic pressure (HHP) can be an alternative to thermal treatment for preservation of dairy products, providing acceptable safety and shelf life with minimal effects on their quality. The main objective of the present study was to evaluate the effect of HHP treatments of 400, 500 or 600 MPa for 5, 10 and 15 min, at 20 °C, on the antirotaviral activity of bovine and ovine whey and buttermilk, along with the effect of HHP and thermal treatments on the activity of some bioactive proteins, such as immunoglobulins and lactoferrin. The antirotaviral activity of dairy fractions was barely affected by treatments below 500 MPa for 15 min, with the greatest activity loss of 17%. High temperature-short time pasteurization was not significantly harmful to the antirotaviral activity of any of the milk proteins tested, which maintained 90–100% of their activity. By contrast, notable differences were observed among proteins regarding the loss of their activity upon low temperature-long time pasteurization and HHP treatments, with losses ranging 0–78% and 0–88%, respectively.

Antibacterial and antifungal activity of LAB bacteriocins derived from the valorization of dairy byproducts using AWDA assay

Antibacterial and antifungal activity of LAB bacteriocins derived from the valorization of dairy byproducts using AWDA assay

Anaerobe Monovergärung von Molke

Acid whey is a dairy byproduct that is suitable for anaerobic conversion to valuable biogas. Treating raw acid whey in a two-stage anaerobic digester unfortunately results in mineral precipitates that inhibit the active biomass. To prevent this, we used a precipitation reactor between stages, after adjusting temperature and pH. We achieved an average reduction of 95.3 percent of chemical oxygen demand and produced the equivalent of 21.6 liters of fossil fuel energy in biogas (192 kWh) for one cubic meter of acid whey.

Lactobacillus plantarum LUHS135 and paracasei LUHS244 as functional starter cultures for the food fermentation industry: Characterisation, mycotoxin-reducing properties, optimisation of biomass growth and sustainable encapsulation by using dairy by-products

Lactobacillus plantarum LUHS135 and Lactobacillus paracasei LUHS244 from fermented cereals were isolated and their properties (carbohydrate metabolism, gas production, ability to survive at a low pH values, growth performance at different temperatures, antimicrobial properties against Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Salmonella enterica, Corynebacter spp, Klebsiella pneomoniae, Enterococcus faecalis, Bacillus cereus, Proteus mirabilis, Clostridium spp., Streptococcus spp., resistance to antibiotics, and reducing properties for aflatoxin B1, ochratoxin A, HT-2 toxin, T-2 toxin, zearalenone) were evaluated. Also, the possibilities to use dairy by-products for biomass growth and encapsulation were investigated. The isolated strains can ferment a broad spectrum of carbohydrates, are tolerant to a low pH values, susceptible to antibiotics and can inhibit the growth of a wide spectrum of pathogenic bacteria. Both strains are good candidates (by using 3% of the mixture of both strains) for the reduction of mycotoxins; these additional properties promote their broader application in the food sector. Whey enriched with 2.5% glucose, 2.0% yeast extract and 0.5% sucrose represents an appropriate alternative substrate for LUHS135 and LUHS244 multiplication and encapsulation, facilitating the production on the industrial scale.

Synthesis of Galactooligosaccharides in Milk and Whey: A Review.

Galactooligosaccharides (GOS) are synthesized by the enzyme β-galactosidase during the hydrolysis of lactose. In this so-called transgalactosylation reaction the galactosyl moiety is transferred to another sugar molecule instead of water resulting in oligosaccharides of different chain lengths and glycosidic linkages. Because their structures are similar to oligosaccharides present in human breast milk, they act as prebiotics, which has been shown for infants and adults to be alike. While so far most of the research to maximize GOS yield has been carried out using buffered lactose solution as a starting material, more and more work is now conducted with dairy by-products such as whey and whey permeate, or even milk, for direct GOS synthesis in order to develop new GOS-enriched dairy products. This review aims to summarize the results obtained with various dairy liquids, and it rates their suitabilities to act as raw material for GOS production. Most of the studies using whey or milk have been carried out with enzymes from Aspergillus oryzae, Kluyveromyces lactis, Bacillus circulans, Streptococcus thermophilus, and several Lactobacillus species. As the initial lactose concentration (ILC) is known to be a crucial factor for high GOS yield, most of the research has been done with concentrated or supplemented milk and whey. However, a clear dependency on ILC could only be observed for the A. oryzae lactase, indicating a strong influence of milk components like minerals and proteins on the transfer activities of most enzymes.

A Comparison Study on the Production and Recovery of Lactic Acid by Fermenting Dairy By-Products with P. acidilactici and Lb. delbrüeckii spp. bulgaricus

This paper provides a comparative study on the fermentative production of lactic acid (LA) by the novel Pediococcus acidilactici KTU05-7, previously isolated from rye sourdough, and the common dairy Lactobacillus delbrueckii spp. bulgaricus using dairy by-products as a substrate. Lactic acid bacteria growth in different fermentation medium, β-d-galactosidase activity, lactose consumption, distribution of l(+)/d(−)-lactic acid isomers and LA purification using a system of membranes were also examined. The highest LA yield (1.9 g/g) was obtained fermenting the whey permeate for 24 h with the novel P. acidilactici. This strain also showed a better growth in whey permeate, a higher tolerance to low pH conditions and tended to produce mainly l(+)-lactic acid, compared to the standard L. bulgaricus. Furthermore, the proteolytic action of P. acidilactici simplified the membrane filtration procedure, and hindered the formation of protein aggregate in fermented broth as compared to L. bulgaricus. The findings of this research suggest that the Pediococcus acidilactici strain has a potential to improve the biotechnological production of LA from dairy industry waste and its recovery by membrane processes.

Determination of lactadherin concentration in dairy by-products by ELISA: Effect of heat treatment and hydrolysis

Lactadherin is a peripheral glycoprotein of the milk fat globule membrane with several attributed biological activities. In this study, we developed an indirect competitive ELISA to determine lactadherin concentration by using a rabbit polyclonal antiserum. The ELISA was applied to quantify lactadherin in several dairy by-products. Of the products tested, raw and commercial buttermilk had the highest concentrations of lactadherin (6.79 and 5.27 mg/g of product, respectively), followed by commercial butter serum (4.86 mg/g), commercial skim milk (4.84 mg/g), and raw whey (1.20 mg/g). The concentration of immunoreactive lactadherin was also determined in dairy by-products after they were subjected to different technological treatments. Thus, raw products were heat treated at combinations of temperature and time typically used in the dairy industry, and commercial products were hydrolyzed using 3 proteolytic enzyme preparations. Heat treatments of whey and buttermilk resulted in a smaller decrease in lactadherin concentration than did hydrolysis as determined by ELISA and electrophoresis. At high temperatures for long durations, the loss of lactadherin was higher in whey than in buttermilk, with the maximal reduction of around 48% found after treating whey at 72°C for 60 min. Hydrolysis of commercial products with proteolytic enzymes resulted in a marked decrease of immunoreactivity within the first 5 min of treatment, which thereafter was constant throughout 4 h of hydrolysis. These results demonstrate that dairy by-products from milk fat processing are good natural sources of lactadherin, although technological processes have to be considered, because they have different effects on lactadherin content.

IMPORTÂNCIA DO DIAGNÓSTICO DA MASTITE SUBCLÍNICA E SEUS IMPACTOS ECONÔMICOS EM PROPRIEDADES LEITEIRAS – REVISÃO DE LITERATURA

Worldwide, mastitis is the disease that exerts the greatest importance on milk quality, as it causes decreased production, loss of milk quality and glandular parenchyma function. The subclinical form determines the greatest economic losses due to the high prevalence (44.9% to 97%) and reduction of milk production between 25.4 and 43%, being 15 to 40 times more frequent than the clinical form, the majority of the estimates indicates that, on average, an affected quarter results in a 30% reduction in its productivity, and an affected cow loses 15% of its production during lactation. The losses can be expressed by the decrease in production, in the alteration of the components that interfere in the process of manufacture of dairy by-products, animal disposal and replacement rates, and treatments of affected cows. Subclinical mastitis has no visible changes in the mammary gland or milk, but the composition of this product undergoes considerable changes in its elements, such as an increase or decrease in chlorine (Cl), sodium (Na) ions. The main methods of diagnosis of subclinical mastitis are: the California Mastitis Test (CMT) and the Somatic Cell Count (CCS) of the individual mammary quarters, methods that allow the producer to make decisions, such as establishing a milking line or measures prophylactics that prevent the spread by the herd.

Antirotaviral Activity of Bovine and Ovine Dairy Byproducts

Rotaviral gastroenteritis is associated with significant morbidity in developed countries and a high rate of infant mortality in developing countries. Diverse studies have demonstrated that a wide range of milk-derived fractions exhibit antirotaviral activity. The present study shows the antirotaviral activity of some bovine and ovine dairy byproducts, buttermilk, butter serum, and milk fat globule membrane (MFGM), and evaluates the effect of cream washing and heat treatment on that activity. Furthermore, the rotavirus-neutralizing activity was evaluated for some MFGM proteins, such as xanthine oxidase and lactophorin. Ovine and bovine buttermilk reached rotavirus-neutralizing values of 51.3 and 32.2%, at 1 mg/mL, respectively. The cream washing process led to a significant decrease in the antirotaviral activity of fractions. This activity was also influenced by heat treatment. Treatment at 75 °C for 20 s caused 24.6 and 36.1% decreases of activity in bovine and ovine buttermilk, respectively, and 85 °C for 10 min caused decreases of 80.9 and 79.0% in both fractions, respectively.

Commercial Mineral Enhanced Dairy By-Products as Sodium Replacers, Antioxidants and Calcium Fortifiers in Sausages

Sausages are perceived as high in Na and with a too high Na:K ratio. Frankfurter type sausages are regarded as important contributors of sodium in the diet and thereby of health risks. Surplus products from the dairy industry are various mineral powders enriched in either potassium, calcium, or phosphate and include various amounts of lactose. Sausages were produced at 3 sodium levels (equivalent to 13, 15, and 17 g NaCl/kg sausage) using 4 different milk ingredients (a dried skimmed milk powder, a calcium enriched milk powder, a potassium enriched powder, and a lactose enriched powder). The sausages with added calcium and potassium enriched milk powders resulted in the hardest sausages when compared at the same sodium level. Milk mineral addition also produced whiter and less red sausages. No effect on rancidity after 6 wk at chill (4 °C) storage was observed by adding milk minerals, when compared with adding dried skimmed milk powder. A significant advantage of using these milk minerals in sausages is that the Na:K ratio can be reduced from an unhealthy (in this study 36) to a far healthier ratio ( ̴ 2) with limited or no taste changes. High additions of milk calcium (6 g/kg), where Ca-phosphates prevail, added as milk mineral, had no influence on sensory bitterness or aftertaste as typically observed for CaCl2 additions. Ca additions to sausages are presently presumed to be an advantage with respect to human nutrition.