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This Technical Research Communication evaluated the influence of various cheese manufacture methods on the composition and in vitro antihypertensive activity of sweet whey samples obtained from miniature models for fresh, Chanco and Gouda-style cheese processing using bulk-tank milks throughout a year. Raw milks from morning milking were standardized, pasteurized and used to obtain sweet whey using cheesemaking protocols for each variety on 200 g scale, as well the use of whey dilution at levels of 0, 15, 30 and 45% in Chanco and Gouda-style making. The composition of sweet whey obtained within each cheesemaking variety was similar among different timepoints of the year (P > 0.05), which was attributed to similar composition of milks and the use standardized cheesemaking protocols used for this study. As expected, the use of whey dilution led to sweet whey samples with reduced levels of total solids (P < 0.05), but they exhibited an improvement of the in vitro antihypertensive properties, which may be attributed to the formation of low-molecular weight bioactive peptides due to increased cheese making times. The results of this study suggest that modifying cheese manufacture protocols may have a direct impact on the bioactive properties of sweet whey. Future work will be required to identify and evaluate the feasibility to purify bioactive peptides obtained from sweet whey.

The interaction between wine tannins and saliva proteins is responsible for wine astringency perception, producing a depletion of salivary proteins and changes on oral friction. In sensorial terms, astringency is described as a dryness and puckering sensation in the mouth, which is related to the "structure" or "body" of red wines. However, these last descriptors, as structure or body, are perceived during wine tasting and commonly related to wine viscosity. To address these differences on sensory response, we hypothesize that tannin-protein interactions could be a key factor involved in the viscosity of red wines/saliva mixtures, just as they are for astringency. We used a rheological method to study the impact of tannin-protein interaction on the viscosity of model wine-saliva systems. Mixtures of model saliva based on mucin and typical astringent compounds, as commercial tannins and gallic acid, were evaluated for their rheological behavior. The viscometric flow of the fluid mixtures was determined, and subsequently, the viscosity was evaluated at a shear rate of 60 s-1 . It was observed that red wines/saliva mixtures exhibit non-Newtonian flow and ascending tannin doses led to an increase in the apparent viscosity. Nephelometric analysis demonstrate that tannin-mucin aggregates were formed, which suggests that these complexes were potentially responsible for the viscosity increases, modifying the rheological behavior of these mixtures. Results from this work propose that tannin-protein interactions are also involved in the underlying mechanism of thickness perception of red wines and rheology could be a complementary instrumental technique for wine mouthfeel characterization.

Control of acidity is critical for cheese quality, as high acidity can be associated with poor flavor and textural attributes. We investigated an alternative method to control cheese acidity, specifically in low-fat (LF) and reduced-fat (RF) milled curd, direct-salted Gouda cheese, which involved altering the initial lactose content of cheesemilk. In traditional Gouda cheese manufacture, a critical technique to control acidity is whey dilution (WD); that is, partial removal of whey and its replacement with water. Direct standardization of the lactose content of milk during the ultrafiltration process could be a simpler and more effective technique to control cheese acidity. This study compared the effect of traditional WD at 2 different levels, 15 and 30% (WD15 and WD30), with the alternative approach of adjustment of the lactose content of milk using low-concentration-factor ultrafiltration (LCF-UF). The composition, texture, functionality, and sensory properties of these LF and RF Gouda cheeses were evaluated. A milled curd, direct-salted cheese manufacturing protocol was used. Milks used for cheesemaking had a lactose-to-casein (L:CN) ratio of approximately 1.8, which is the typical ratio found in milk, whereas milks prepared with lactose standardization (LS) were made from UF concentrated milks with water added during filtration to achieve a L:CN ratio of approximately 1.1. Cheeses made with LS exhibited lower lactose and lactic acid contents than WD30 and WD15, leading to significantly higher pH values in the cheese. Dynamic small-amplitude oscillatory rheology indicated that use of LS led to cheeses with a lower crossover temperature (melting point) than the cheeses made with WD. Cheeses made with LS had lower insoluble Ca contents, likely caused by the addition of water required to achieve the lower L:CN ratio in these milks. Sensory analysis also indicated that LS cheeses had lower acidity and softer texture. These results suggest that standardization of the L:CN ratio of milk could be a useful alternative to WD (or a curd rinse step) to reduce acidity in cheeses. In addition, LS could be used to help soften texture and increase meltability, if desired in lower-fat cheese types.

In humid temperate regions, forage turnip (Brassica rapa ssp. rapa) and forage rape (Brassica napus ssp. biennis) are common fodder crops used for dairy cattle during the summer season. However, there is little scientific information regarding the use of brassicas and their effect on the fatty acid (FA) profile in blood, milk, and milk products. The aim of this study was to evaluate the effect of forage brassica supplementation in dairy cows on the FA profile of blood plasma, milk, and cheese, and on the sensory characteristics of Chanco and Ricotta cheeses. Twelve multiparous dairy cows (Holstein Friesian) were housed and submitted to a 3 × 3 replicated (n = 3) Latin square design with 3 treatments (control, turnip, or rape) in 3 periods of 21 d each (14 d of diet adaptation and 7 d of measurements). The control diet consisted of 16.20 kg of grass silage (Lolium perenne), 2.25 kg of soybean bran, and 2.25 kg of commercial concentrate, all on a dry matter (DM) basis. In the treatments with forage brassicas, 24.15% of the total DM was replaced by turnip or rape; thus, they consisted of 12.25 kg of silage, 2.25 kg of soybean bran, 1.2 kg of concentrate, and 5 kg of turnip or rape (DM basis). A principal components analysis was performed on the results of the cheese sensory evaluation. Supplementation with turnip or rape modified the profile of FA in blood plasma and milk, increasing the saturated fraction, mainly short- and medium-chain FA, and decreasing the mono- and polyunsaturated FA. In the sensory evaluation, diet did not affect any of the 18 attributes evaluated. However, in the principal components analysis, cheeses made with milk from animals fed turnip and rape were differentiated by increased odor, flavor, spiciness, bitterness, and acidity. Overall, brassicas can be used as an alternative forage source with no negative effects on sensory characteristics of cheeses.

The research reported in this Research Communication evaluates the effect of milk acidification on the physicochemical and sensory properties of Licor de Oro (or Gold Liqueur; LO), a traditional alcoholic beverage produced in Chiloé island, Chile, which is made by mixing milk acidified with lemon juice and alcohol at a ratio of 1.0:1.0, along with sugar and other spices. The mixture is stored for a couple of weeks and then filtered to obtain a product with a yellowish-transparent appearance, sweetness and acidic taste, milky and alcoholic notes. The lack of information regarding LO processing, mainly in the amount of acid added to the mixture, leads to products of highly variable quality. Thus, the objective of this study was to evaluate the effect of milk acidification on the physicochemical and sensory properties of LO. Raw milk was acidified using citric acid to six different pH values: 6.7 (control), 6.0, 5.3, 4.6, 3.9 and 3.2. These milk treatments were then used to make LO. A decrease of milk pH led to LO with higher levels of sensorial and titratable acidity. LO obtained at pH 6.7 and 6.0 had higher levels of total protein than other treatments, leading to excessive turbidity. In contrast, treatments made at pH ≤5.3 had a typical transparent appearance of LO. These results suggest that a minimum level of milk acidification is required to obtain LO with desired appearance and composition.

Brassica crops such as kale and swede can be supplied to cow diets during winter, however little is known about the effects of feeding those forage brassicas to lactating cows on cheese nutritional characteristics of milk and cheese. This study evaluated the effect of including kale or swede in pasture-fed lactating dairy cow diets on chemical composition, fatty acid (FA) profile, and sensory characteristics of Chanco-style cheese. Twelve early-lactation cows were used in a replicated (n = 4) 3 &times, 3 square Latin square design. The control diet consisted of (DM basis) 10.0 kg of grass silage, 4.0 kg of fresh grass pasture, 1.5 kg soybean meal, 1.0 kg of canola meal, and 4.0 kg of cereal-based concentrate. The other treatments replaced 25% of the diet with swede or kale. Milk yield, milkfat, and milk protein were similar between treatments as were cheese moisture, fat, and protein. Swede and kale increased total saturated cheese FA while thrombogenic index was greater in swede, but color homogeneity and salty flavor were greater while ripe cheese aroma less than for kale. Kale or swede can be used in the diet of pasture-fed lactating dairy cows without negative effects on milk production, milk composition, or cheese composition. However, kale and swede increased total cheese saturated FA.

This Technical Research Communication evaluated the influence of various cheese manufacture methods on the composition and in vitro antihypertensive activity of sweet whey samples obtained from miniature models for fresh, Chanco and Gouda-style cheese processing using bulk-tank milks throughout a year. Raw milks from morning milking were standardized, pasteurized and used to obtain sweet whey using cheesemaking protocols for each variety on 200 g scale, as well the use of whey dilution at levels of 0, 15, 30 and 45% in Chanco and Gouda-style making. The composition of sweet whey obtained within each cheesemaking variety was similar among different timepoints of the year (P0.05), which was attributed to similar composition of milks and the use standardized cheesemaking protocols used for this study. As expected, the use of whey dilution led to sweet whey samples with reduced levels of total solids (P0.05), but they exhibited an improvement of the in vitro antihypertensive properties, which may be attributed to the formation of low-molecular weight bioactive peptides due to increased cheese making times. The results of this study suggest that modifying cheese manufacture protocols may have a direct impact on the bioactive properties of sweet whey. Future work will be required to identify and evaluate the feasibility to purify bioactive peptides obtained from sweet whey.

The study aimed at determining the antioxidant effect of natural extracts on the oxidative quality and color variation of rainbow trout fillets during storage at 4 °C. The fillets were marinated and samples from the belly flap area and Norwegian quality cuts were used for lipid oxidation determination while the dorsal region was used for color measurements. The fillets were marinated with the different treatments: 470 mg l-1 of oregano extract, 6.84 ml l-1 of quillaia extract, 7.2 ml l-1 of rosemary extract and 2 ml l-1 of a synthetic antioxidant. Maximum TBARS (Thiobar-bituric acid reactive substances) values of belly flap and Norwegian quality cuts occurred at five and six days of storage, respectively. The susceptibility of treatments to lipid oxidation in decreasing order was: control>quillaia >oregano>rosemary>synthetic antioxidant. An increase in lightness (L*) and redness (a*) were observed for rosemary and quillaia extracts when compared to control samples. Marinates with natural antioxidants may be an al-ternative for extending shelf-life of trout fillets at least during the first six days of storage at 4 °C.

The objective of this study was to evaluate the physicochemical and texture changes of the Manchego-style cheese produced from hair sheep (Pelibuey) throughout 180 days of ripening, as well as consumer&rsquo, s acceptance. Cheese pH was constant from 1 to 180 days of ripening. Moisture, water activity, fat, elasticity and hardness decreased from day 1 to day 180, while protein, trichloroacetic acid-soluble N and free amino acid increased. Cheese lightness decreased as ripening time increased, while elasticity and hardness decreased. Principal Component Analysis was useful in discriminating cheeses according to their physicochemical composition and that allowed cheeses to be classified in two groups according to their ripening time and this resulted in those with less than 60 days and those with more than 90 days of ripening. Compared with cheeses ripened at 1 and 90 days, aged cheeses at 180 days reduced scores for appearance, color, odor, taste, texture and overall acceptance. Overall, Manchego-style cheeses from hair sheep had the usual ripened-cheese physicochemical changes.

The aim of the study was to characterize Chilean consumers of commercial fluid milk and determine if sociodemographic characteristics, knowledge and/or perception on nutritive components of milk affect its consumption. A face-to-face interview was conducted through a stratified random sampling with 501 persons in the Province of Santiago, Metropolitan Region, Chile. The interviews were conducted at the entrance of major supermarkets from 5 different municipalities of the Province of Santiago. Interviews were performed from 10.00 h a.m to 13.00 h p.m. and from 15.00 hours to 17.30 h p.m. every day. Sixteen percent of respondents declared not consuming milk due to animal cruelty followed by self-reported lactose intolerance among other reasons. The most consumed types of milk were whole (25 %), semi-skimmed (24 %) and skimmed (25 %) followed by other types. The majority of respondents that consume milk declared to do it at home (93 %; n = 393), while the rest (7 %; n = 30) declared to consume milk elsewhere (at a coffee shop, restaurant, as a guest, etc.). Participants declared to make their purchase by prioritizing price followed by brand, type of milk, expiration date, nutritional information, packaging, and milk origin. Respondents (86 %) declared to know some nutritional benefits from drinking milk: 47.6 % said that milk was important due to its mineral supply, followed by supply of vitamins (17 %), proteins (17.1 %), fat (13.5 %), sugars (4.5 %) and other components (0.4 %). Most of the answers were associated in some degree with sociodemographic factors. Overall, women declared to consume more skimmed milk whereas, males declared to consume in first place whole milk. Respondents between 18-35 years old declared to consume skimmed and whole milks, while respondents with more than 55 years declared to consume fortified milk followed by semi-skimmed. Consumption of skimmed milk was higher in the high-income socioeconomic class whereas the low-income socioeconomic class resulted in higher consumption of whole milk.

Because of their unique composition and properties, milk and dairy products represent excellent growth media for many pathogenic microorganisms. Staphylococcus aureus, Salmonella spp., Listeria monocytogenes and Escherichia coli O157:H7 are the most frequent potential pathogens associated with milk or dairy products in industrialized countries and are therefore the main microbiological hazards linked to raw milk and raw cheese. This review summarizes the scientific information about outbreaks related to foodborne pathogens in dairy products and highlights the increasing application of molecular approaches to detect and identify the bacteria responsible for these outbreaks. Molecular techniques have facilitated the rapid detection and identification of foodborne pathogens, which has been crucial for current surveillance and outbreak control.

Cheese translucency is influenced by fat content, ripening and temperature and is traditionally determined by CIELAB whiteness. However, translucency is also affected by thickness of materials. The Kubelka-Munk method ( K/S ) estimates the ratio of absorbance to scatter from whiteness measurements on thin layers of materials above white and black backgrounds. The effect of fat content and temperature on Cheddar cheese translucency was evaluated using K/S and CIELAB methods. Cheddar cheeses varying in fat composition were made and translucency was measured during heating/cooling at 2 and 180 d of ripening. Low fat content in cheese was found to be related to high translucency at 60 °C, a reversible protein aggregation led to a reduction of translucency. Translucency increased as cheeses aged. CIELAB and K/S methods were highly correlated; K/S could therefore be useful for estimating cheese translucency.

A methodology to discriminate retail cheeses by principal component analysis (PCA) and consequent orthogonal partial least squares discrimination analysis (OPLS-DA) using fatty acid (FA) profile differences is reported. Multivariate analysis included retail cheeses from 3 different varieties (Gouda, Chanco and Mantecoso) and 2 distinct scales of production. PCA was useful in discriminating cheeses according to their variety, but it did not allow differentiation according to the scale of production. Gouda and Chanco cheeses were differentiated by saturated FAs (C6:0, C8:0, C10:0, C11:0, C12:0, C14:0, C16:0, and C18:0) whereas Mantecoso cheese was discriminated by specific (C4:0, C14:1, C16:1, C17:0, and C18:1) FAs. OPLS-DA differentiated cheeses based on the scale of production, which would be related to the feeding regime of the dairy cattle. C16:1c9 showed the strongest association with large-scale production cheeses and intensive systems, while C15:0c9, C17:0, C20:1n9, C20:4n6, and C22:2 were characteristic of artisanal cheeses and extensive feeding regimes., This study was partly sponsored by a research grant from Fondo Nacional de Desarrollo Científico y Tecnológico, Chile (FONDECYT 1170400) and Vicerrectoría de Investigación of Pontificia Universidad Católica de Chile (Proyecto Puente P1608). Pilar Gómez-Cortés gratefully acknowledges a Juan de la Cierva-Incorporación research contract from the Spanish Ministry of Economy, Industry and Competitiveness. Rodrigo A. Ibáñez acknowledges the support of Programa de Inserción Académica (Vicerrectoría Académica of Pontificia Universidad Católica de Chile).

The effects of dietary unrefined olive oil (OO) residues and hydrogenated vegetable oil (HVO) on the fatty acid profiles of milk and cheese and the sensory characteristics of cheeses were determined. For 9 weeks, animals were fed a control diet with no added lipid (n = 5 cows), or fat-supplemented diets containing OO or HVO (in both cases n = 5 cows; 30 g kg−1 dry matter). Compared with control and HVO, OO increased C18:1 cis-9, and C18:3 cis-9, cis-12, cis-15 fatty acids in milk; and also increased C18:1 trans-10, C18:1 trans-11, C18:1 cis-9, C18:2 cis-9, trans-11 and C18:3 cis-9, cis-12, cis-15 fatty acids in cheeses. OO reduced the number of holes, overall odour and acidity of cheeses, whereas HVO increased the cow milk odour, bitterness and acidity of cheeses. Overall, OO can improve the cheese fatty acid profile, but with adverse effects on sensory attributes., This study was partly sponsored by a research grant from FONDECYT 1170400 (Fondo Nacional de Desarrollo Científico y Tecnológico, Chile) and Vicerrectoría de Investigación of Pontificia Universidad Católica de Chile (Proyecto Puente P1608).

Hydrocolloids have been extensively studied in low-fat cheeses as a way to improve defects associated with fat reduction, which are often related to texture and functionality (meltability). Pectin is a polysaccharide obtained from plant cells and is commonly used as a stabilizer for acidified dairy beverages. This work aimed to evaluate the effect of three types of commercial pectins on the characteristics of reduced-fat Cheddar cheese during a ripening period of 180 days. Five Cheddar cheeses were made: full-fat control (FF), reduced-fat control (RF), and reduced-fat cheeses with amidated (RA), high-methoxy (RH), or low-methoxy (RL) pectin added to milk prior processing at concentrations of 0.175%, 0.100%, and 0.075% (w/w), respectively; levels were chosen to avoid phase separation of the casein micelles, due to depletion flocculation. Addition of amidated pectin markedly increased the moisture content of the experimental cheese (~49%), compared to RF (~45%; P 100 N in RF at 180 days; P 85 versus

The manufacture of traditional cheese varieties by mixing different proportions of cow and goat milk has become a common practice to obtain products with different appearance, texture and flavor. This study aimed to evaluate the effect of increasing the proportion of goat milk in the chemical, textural and sensory properties of Chanco-style cheese, a traditional variety from Chile and produced with pasteurized cow milk. A standardized cheese manufacture process was performed based on milk composition and differing in the proportions of cow and goat milk: 100% cow and 0% goat (100C), 67% cow and 33% goat (67C), 33% cow and 67% goat (33C), and 0% cow and 100% goat (0C). Similar composition, pH and melting were observed among treatments, but main differences were found in degradation of αs1-CN and peptide profile, levels of C6:0, C8:0, C10:0, C14:0 and C14:1 cis-9 fatty acids, fracture strain and whiteness index. Sensory analysis indicated that increasing proportions of goat milk led to cheeses with higher scores in whiteness and goat flavors. These results suggest that increasing proportions of goat milk in the manufacture of Chanco-style cheese could be a good alternative for consumers that are constantly searching for products with different properties.