High-pressure processing (HPP) and low-temperature storage (0 degrees C) were explored as alternatives to freezing for extending the performance shelf life of low-moisture, part-skim (LMPS) mozzarella intended for export. Batches (n = 5) of reduced Na LMPS mozzarella were manufactured using camel chymosin as a lower proteolytic type of rennet. Cheeses were stored for 2 wk at 4 degrees C, divided into control (non-HPP) and HPP (600 MPa for 3 min) groups, and stored at 3 different temperatures (4, 0, and -18 degrees C) for 365 d. Analyses were performed at 0, 90, 150, 210, 270, and 365 d of storage. Frozen and 0 degrees C samples (similar to 2.3 kg) were thawed/tempered at 4 degrees C for 1 wk before analysis. Urea PAGE and quantification of the pH 4.6 soluble N over time were used to monitor primary proteolysis. Body and rheological properties were monitored using texture profile analysis (TPA) and dynamic low-amplitude oscillatory rheology. Changes in flavor, body, shred properties, and pizza performance were evaluated using quantitative descriptive analysis with 12 trained panelists using a 15-point scale. High-pressure processing treatment caused similar to 5 log cfu/mL reduction in starter counts, partial solubilization of the insoluble Ca, and a small pH increase (from similar to 5.2 to 5.3). The rate of primary proteolysis was reduced by HPP and low-temperature storage. High-pressure processing treatment reduced initial cheese hardness, but no further significant decrease was observed over storage time, whereas the hardness of non-HPP samples decreased over the 365 d of storage, apart from the frozen samples. In pizza applications, blister quantity development and loss of strand thickness were limited by storage at -18 degrees C. Freezing LMPS mozzarella to -18 degrees C gave the least changes in proteolysis and pizza performance over the 365 d of study, storage of cheese at 0 degrees C slowed the loss of hardness and the deterioration of pizza performance attributes. The combination of HPP and 0 degrees C storage of cheese resulted in little change in blistering quantity of pizza during the 365 d of study, whereas cheese stored at 0 degrees C had blisters covering much of the pizza after this extended storage time. Combining HPP with low-temperature storage is a promising alternative approach to freezing for the extension of the shelf life of LMPS mozzarella.

The manufacturing method of String cheese is similar to Mozzarella, but the hot curd is extruded through narrow tubes or pipes, which align the protein fibers that provides the characteristic ability for consumers to pull strings from this cheese. Firmness is another important performance attribute for consumers who just bite into the String cheese without peeling off strings. There have only been a few studies on String cheese, but it is known that stringiness and firmness decrease during prolonged storage, which is a particular challenge for exporting String cheese. We explored 2 treatments to try to retain the stringiness and firmness of String cheese for longer storage periods. The techniques used were high pressure processing (HPP; 600 MPa for 3 min) and reduced storage temperature (0°C). In other cheese varieties, these techniques have helped extend the performance shelf-life. We tested these techniques using the 2 main types of commercial String cheese: direct acid (DASC) and cultured String cheese (CSC), that were obtained from 2 different manufacturing facilities. The DASC had higher fat (∼2.2%) and higher pH values (∼0.2 units) compared with the CSC. The CSC had higher protein content (∼3.4%), higher insoluble calcium content (∼8 mg insoluble Ca/g protein) and higher hardness values (∼4 N) compared with the DASC. Due to the compositional differences, the 2 varieties were statistically analyzed separately for all other attributes. In both cheese types, HPP caused an immediate reduction in stringiness, some solubilization of insoluble calcium, and a slight increase in the cheese pH values. HPP also caused a slight increase in the TPA hardness of the CSC samples until 14 d (possibly due to a slight increase in cheese pH). The use of the 0°C storage temperature reduced proteolysis and helped retain firmness during storage. Low temperature storage could help extend the performance shelf-life of String cheese by a couple of months, but HPP was not suitable as the process caused an immediate reduction in stringiness due to the disruption of the matrix induced by the HPP treatment.

A growing number of companies within the cheese-making industry are now using high-protein (e.g., 4-5%) milks to increase cheese yield. Previous studies have suggested that cheeses made from high-protein (both casein and whey protein; WP) milks may ripen more slowly; one suggested explanation is inhibition of residual rennet activity due to elevated WP levels. We explored the use of microfiltration (MF) to concentrate milk for cheese-making, as that would allow us to concentrate the casein while varying the WP content. Our objective was to determine if reducing the level of WP in concentrated cheese milk had any impact on cheese characteristics, including ripening, texture, and nutritional profile. Three types of 5% casein standardized and pasteurized cheese milks were prepared that had various casein:true protein (CN:TP) ratios: (a) control with CN:TP 83:100, (b) 35% WP reduced, 89:100 CN:TP, and (c) 70% WP reduced, 95:100 CN:TP. Standardized milks were preacidified to pH 6.2 with dilute lactic acid during cheese-making. Composition, proteolysis, textural, rheological, and sensory properties of cheeses were monitored over a 9-mo ripening period. The lactose, total solids, total protein, and WP contents in the 5% casein concentrated milks were reduced with increasing levels of WP removal. All milks had similar casein and total calcium levels. Cheeses had similar compositions, but, as expected, lower WP levels were observed in the cheeses where WP depletion by MF was performed on the cheese milks. Cheese yield and nitrogen recoveries were highest in cheese made with the 95:100 CN:TP milk. These enhanced recoveries were due to the higher fraction of nitrogen being casein-based solids. Microfiltration depletion of WP did not affect pH, sensory attributes, or insoluble calcium content of cheese. Proteolysis (the amount of pH 4.6 soluble nitrogen) was lower in control cheeses compared with WP-reduced cheeses. During ripening, the hardness values and the temperature of the crossover point, an indicator of the melting point of the cheese, were higher in the control cheese. It was thus likely that the higher residual WP content in the control cheese inhibited proteolysis during ripening, and the lower breakdown rate resulted in its higher hardness and melting point. There were no major differences in the concentrations of key nutrients with this WP depletion method. Cheese milk concentration by MF provides the benefit of more typical ripening rates.

PurposeWe sought to identify factors associated with long-term changes in health-related quality of life (HRQOL) among 3 groups of older patients (pts) with advanced heart failure (HF) undergoing heart transplantation (HT), with or without pre-transplant mechanical circulatory support (MCS), or long-term MCS, if ineligible for HT.MethodsFrom 10/1/15-12/31/18, 393 pts (60-80 years) were enrolled from 13 U.S. sites, including 239 pts awaiting HT (118 with and 121 without MCS) and 154 long-term MCS pts. Of these, 151 pts (95 HT pts [34 with MCS and 61 without MCS before HT] and 56 long-term MCS pts) had 24-month follow-up data. The EQ-5D Visual Analog Scale (VAS; 0-100 [worst-best health state]) and KCCQ-12 overall summary score (OSS; 0-100 [poor-excellent health status]) were collected at baseline (closest to surgery) and 24-months. Analyses included ANOVA, paired t-tests, and multivariable linear regression.ResultsAverage age at HT or long-term MCS implant (n=151) was 66.8 ±4.5 years, 80% were male, and 81% were white. At baseline, long-term MCS pts, compared with HT pts awaiting HT with MCS and those awaiting HT on medical therapy, had the lowest VAS scores (48.7±20.8 vs 65.9±21.0 vs 51.6±25.4, p=0.002) and KCCQ-12 OSS (37.1±20.9 vs 56.5±25.6 vs 46.4±20.5, p<0.001). HRQOL improved significantly in all 3 groups by 24 months (p<0.001); however, long-term MCS pts, compared with HT pts awaiting HT with MCS and those awaiting HT on medical therapy, still had the lowest VAS scores (70.9±19.7 vs 81.8±14.6 vs 86.2±12.1, p<0.001) and KCCQ-12 OSS (63.3±24.1 vs 85.3±16.0 vs 90.0±14.3, p<0.001). Multivariable models (Table) indicate that baseline HRQOL and undergoing HT, with or without MCS, are the strongest predictors of improvement in HRQOL.ConclusionAmong pts with advanced HF requiring HT or MCS, improvement in HRQOL was greatest in those undergoing HT with or without MCS pre-HT and those with worse baseline HRQOL. These findings may inform advanced HF pts of anticipated HRQOL outcomes with alternative therapies. We sought to identify factors associated with long-term changes in health-related quality of life (HRQOL) among 3 groups of older patients (pts) with advanced heart failure (HF) undergoing heart transplantation (HT), with or without pre-transplant mechanical circulatory support (MCS), or long-term MCS, if ineligible for HT. From 10/1/15-12/31/18, 393 pts (60-80 years) were enrolled from 13 U.S. sites, including 239 pts awaiting HT (118 with and 121 without MCS) and 154 long-term MCS pts. Of these, 151 pts (95 HT pts [34 with MCS and 61 without MCS before HT] and 56 long-term MCS pts) had 24-month follow-up data. The EQ-5D Visual Analog Scale (VAS; 0-100 [worst-best health state]) and KCCQ-12 overall summary score (OSS; 0-100 [poor-excellent health status]) were collected at baseline (closest to surgery) and 24-months. Analyses included ANOVA, paired t-tests, and multivariable linear regression. Average age at HT or long-term MCS implant (n=151) was 66.8 ±4.5 years, 80% were male, and 81% were white. At baseline, long-term MCS pts, compared with HT pts awaiting HT with MCS and those awaiting HT on medical therapy, had the lowest VAS scores (48.7±20.8 vs 65.9±21.0 vs 51.6±25.4, p=0.002) and KCCQ-12 OSS (37.1±20.9 vs 56.5±25.6 vs 46.4±20.5, p<0.001). HRQOL improved significantly in all 3 groups by 24 months (p<0.001); however, long-term MCS pts, compared with HT pts awaiting HT with MCS and those awaiting HT on medical therapy, still had the lowest VAS scores (70.9±19.7 vs 81.8±14.6 vs 86.2±12.1, p<0.001) and KCCQ-12 OSS (63.3±24.1 vs 85.3±16.0 vs 90.0±14.3, p<0.001). Multivariable models (Table) indicate that baseline HRQOL and undergoing HT, with or without MCS, are the strongest predictors of improvement in HRQOL. Among pts with advanced HF requiring HT or MCS, improvement in HRQOL was greatest in those undergoing HT with or without MCS pre-HT and those with worse baseline HRQOL. These findings may inform advanced HF pts of anticipated HRQOL outcomes with alternative therapies.

In the manufacture of cream cheese, sweet cream and milk are blended to prepare the cream cheese mix, although other ingredients such as condensed skim milk and skim milk powder may also be included. Whey cream (WC) is an underutilized fat source, which has smaller fat droplets and slightly different chemical composition than sweet cream. This study investigated the rheological and textural properties of cream cheeses manufactured by substituting sweet cream with various levels of WC. Three different cream cheese mixes were prepared: control mix (CC; 0% WC), cream cheese mixes containing 25% WC (25WC; i.e., 75% sweet cream), and cream cheese mixes with 75% WC (75WC; i.e., 25% sweet cream). The CC, 25WC, and 75WC mixes were then used to manufacture cream cheeses. We also studied the effect of WC on the initial step in cream cheese manufacture (i.e., the acid gelation process monitored using dynamic small amplitude rheology). Acid gels were also prepared with added denatured whey proteins or membrane proteins/phospholipids (PL) to evaluate how these components affected gel properties. The rheological, textural, and sensory properties of cream cheeses were also measured. The WC samples had significantly higher levels of PL and insoluble protein compared with sweet cream. An increase in the level of WC reduced the rate of acid gel development, similar to the effect of whey phospholipid concentrate added to mixes. In cream cheese, an increase in the level of added WC resulted in significantly lower storage modulus values at temperatures <20°C. Texture results, obtained from instrumental and sensory analyses, showed that high level of WC resulted in significantly lower firmness or hardness values and higher stickiness compared with cream cheeses made with 25WC or CC cream cheeses. The softer, less elastic gels or cheeses resulting from the use of high levels of WC are likely due to the presence of components such as PL and proteins from the native milk fat globule membrane. The use of low levels of WC in cream cheese did not alter the texture, whereas high levels of WC could be used if manufacturers want to produce more spreadable products.

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.

Women approached who did not enroll in SUSTAIN-IT were more likely than men to refuse to participate. Reasons for refusal varied for both women and men based on type of advanced HF therapy. Our novel findings may provide tailored guidance when recruiting men and women in clinical trials.

Stabilizers are routinely added during cream cheese manufacture to help prevent syneresis during storage. We investigated how different types of stabilizers affected the texture, rheology, and sensory properties of cream cheese. Cream cheeses were manufactured with 0.33% xanthan gum (XG), locust bean gum (LBG), guar gum (GG), or a combination (CBN) of these 3 stabilizers (0.11% of each). Rheological properties of solutions of the individual stabilizers and their combination (equal amounts) were also determined under conditions similar to the aqueous phase of cream cheese (0.6% gum, 1.8% NaCl, and pH 5). Dynamic small amplitude rheological properties of the cream cheeses were measured during heating from 5 to 80°C at the rate of 1°C/min and cooling at the same rate (because most cream cheese is hot packed/filled before cooling). Measured rheological parameters included storage modulus (G') and loss tangent. Hardness of cream cheeses was determined by texture profile analysis. Quantitative spectrum descriptive sensory analysis was also performed. Distinct differences were observed between the rheological properties of solutions of the individual stabilizers and the CBN containing all the stabilizers. Results showed that CBN solution formed a strong, thermally reversible gel due to synergistic interaction between stabilizers, whereas XG solution formed a weak gel that was not greatly affected by temperature. Solutions of LBG and GG behaved rheologically as entangled polymer solutions. In the high-temperature (>35°C) region, cream cheeses made with XG and CBN showed higher G' values compared with other cream cheeses. The G' values were higher for XG- and CBN-stabilized cream cheeses than LBG- and GG-stabilized cream cheeses at several temperature regions during the cooling cycle. The CBN-stabilized cream cheeses had higher hardness values than the cream cheeses manufactured with the individual stabilizers. Differences were observed between the sensory attributes of cream cheeses stabilized with CBN and those made with individual stabilizers. At low temperatures, the higher hardness and G' values of CBN-stabilized cream cheeses could be due to synergistic interaction between XG and galactomannans. The higher elasticity of XG-stabilized cream cheeses at high temperatures could be due to its higher thermal stability. This study showed that the stabilizers added during manufacture of cream cheese affected its texture, rheological, and sensory properties.

Some European dairies use low concentration factor microfiltration (MF) in their cheese plants. Removal of whey protein (WP) from milk before cheesemaking using microfiltration without concentration provides the opportunity to produce a value-added by-product, milk-derived whey. However, few studies have focused on the effects on cheese properties caused by the depletion of WP from cheese milk. Most studies have concentrated cheese milk using MF in addition to depletion of WP. In our approach, cheese milk was not concentrated during WP depletion using MF. We wanted to quantify residual WP levels in cheese made from MF milk and to explore whether WP depletion from milk would influence functionality, nutritional profile, and cheese quality during ripening. Casein (CN) contents for all milks were kept at ∼2.5%, to eliminate the confounding factor of concentration of CN, which was observed in some previous MF studies. Cheese milks had similar ratios of CN to fat. Three standardized milks were produced with various CN:true protein (TP) ratios: (a) control with a CN:TP ratio of 83:100, (b) 35% WP depletion, 89:100 CN:TP, and (c) 70% WP depletion, 95:100 CN:TP. Cheddar cheeses were made from MF milk with various WP depletion levels and aged for 9 mo, and their functionality was evaluated during ripening. We found no major differences in cheese composition or pH values between samples. Cheese yield, solids recovery, and nitrogen recovery were slightly higher in the 95:100 CN:TP cheeses compared with the control. These enhanced recoveries reflect that MF-treated milk started with a higher fraction of CN-based protein solids, rather than WP solids. The standardized milk from the 95:100 CN:TP treatment also had a slightly higher fat content compared with the control, likely helping to increase cheese yield. Rheological properties of cheeses during heating were similar between treatments. Hardness initially decreased with age for all cheeses due to proteolysis or solubilization, or both, of calcium phosphate. Maximum loss tangent (LT), an index of cheese meltability, was slightly lower for the control cheese until 30 d of ripening, but after 30 d, all treatments exhibited similar maximum LT values. The temperature where LT = 1 (crossover temperature), an index of softening point during heating, was slightly lower for MF cheese compared with the control cheeses during ripening. Microfiltration treatment had no significant influence on proteolysis. Sensory properties were similar between the cheeses, except for bitterness. Bitterness intensity was slightly lower in the MF cheeses than in the control cheeses and increased in all cheeses during ripening. We detected no major differences in the concentrations of key nutrients or vitamins between the various cheeses. Depletion of WP in cheese milk by MF did not negatively affect cheese quality, or its nutritional profile, and resulted in similar cheesemaking yields.

177 Effect of different aging conditions on the physicochemical and textural characteristics of an artisanal cheese produced in South African rural communities. F. Nyamakwere1, M. Busti2, E. Raffrenato*1, P. A. Gouws3, K. Dzama1, and G. Esposito1, 1Department of Animal Sciences, Stellenbosch University, Stellenbosch, South Africa, 2Caseificio della Famiglia Busti, Fauglia, Italy, 3Department of Food Science, Stellenbosch South Africa.