Effect of the use of three different lamb paste rennets on lipolysis of the PDO Pecorino Romano Cheese

Two rennet pastes were prepared from lambs on different diets, and then, together with a commercial lamb rennet paste, were used to produce protected designation of origin (PDO) Pecorino Romano cheeses. Chymosin activity and lipolytic activity were higher in the prepared rennets than in the commercial rennet. Lipolysis was greatest in cheese produced with one of the prepared rennets. Both quantitative and qualitative differences in free fatty acids were found in the cheeses. The taste of cheeses made with the prepared rennets was preferred by an expert sensory panel and also considered more piquant than that of cheese made with commercial rennet. The results indicate that both the diet of the lambs and slaughtering conditions should be regulated to produce rennet that preserves the traditional characteristics of PDO Pecorino Romano cheese. Both lipolytic and proteolytic properties of rennet pastes should be standardised for the preparation of such cheeses.     

Factors affecting consumers' preferences for and purchasing decisions regarding pasteurized and raw milk specialty cheeses

Eight hundred ninety consumers at a local food festival were surveyed about their specialty cheese purchasing behavior and asked to taste and rate, through nonforced choice preference, 1 of 4 cheese pairs (Cheddar and Gouda) made from pasteurized and raw milks. The purpose of the survey was to examine consumers’ responses to information on the safety of raw milk cheeses. The associated consumer test provided information about specialty cheese consumers’ preferences and purchasing behavior. Half of the consumers tested were provided with cheese pairs that were identified as being made from unpasteurized and pasteurized milk. The other half evaluated samples that were identified only with random 3-digit codes. Overall, more consumers preferred the raw milk cheeses than the pasteurized milk cheeses. A larger portion of consumers indicated preferences for the raw milk cheese when the cheeses were labeled and thus they knew which samples were made from raw milk. Most of the consumers tested considered the raw milk cheeses to be less safe or did not know if raw milk cheeses were less safe. After being informed that the raw milk cheeses were produced by a process approved by the FDA (i.e., 60-d ripening), most consumers with concerns stated that they believed raw milk cheeses to be safe. When marketing cheese made from raw milk, producers should inform consumers that raw milk cheese is produced by an FDA-approved process.     

Salty taste in dairy foods: can we reduce the salt?

Sodium can be found in many sources of the US diet. Dietary guidelines currently suggest a maximum intake of 2,300 mg of sodium (6 g of sodium chloride) per day, whereas the average consumer intake is 3,600 mg of sodium (9 g of sodium chloride) per day. The main health concern with high consumption of sodium is hypertension. The objectives of this study were to identify the salty taste intensity of sodium chloride in water and various dairy food matrices, and to identify the just-noticeable difference in concentration at which consumers noticed a decrease in salty taste in these food products. Solutions and food products (water, cheese sauce, cottage cheese, and milk-based soup) were prepared with sodium chloride ranging in concentration from 0.008 to 0.06 M. Seventeen panelists evaluated the salty intensity of each product in triplicate using a magnitude estimation scale. In subsequent tests, panelists (n = 50) evaluated salty intensity of these food products in separate sessions using an ascending force choice method to determine the just-noticeable difference. Consumer acceptance tests (n = 75 consumers) were conducted with cottage cheeses with and without sodium reductions and under conditions with and without health benefits of sodium reduction. The magnitude estimation scale data were log-transformed, and all data were analyzed by ANOVA with Fisher's least significant difference for means separation. The linear proportion of the power function in the salty taste intensity curve for sodium chloride solutions and the 3 foods was between 0.03 and 0.20 M. Consumers were able to notice and correctly identify reductions in salt concentration of less than 20% in all products. When consumers were informed of sodium reduction and its health benefits before tasting cottage cheese with lower sodium (4-12%), overall liking scores for the lower sodium cottage cheeses were not different from higher sodium cottage cheeses. These results suggest that reducing sodium in cheese sauce, cottage cheese, and milk-based soups may be challenging and that exploration of sodium chloride alternatives in these foods is warranted. Appropriate product positioning or advertising may be beneficial to consumer acceptance of lower sodium types of products.     

BRNING TIME AND SMOKING INFLUENCE ON ACCEPTABILITY OF IDIAZABAL CHEESE

Brining time and traditional smoking effects on sensory characteristics (appearance, odor, texture, taste and aftertaste) during ripening of Idiazabal cheese were studied in terms of acceptability. The range of brining time (12, 24 and 36 h) considered in this study showed little effect on sensory parameters. In longer brined cheeses, an improvement of rind acceptability was observed especially at the beginning of the ripening period. In young products the texture of the more salted cheese was preferred, in hard cheeses consumers preferred the less salty ones. The traditional smoking process had a greater effect on sensory parameters perceived by consumers than brining time did. It was observed that smoking had a positive influence on acceptability of rind, paste color and eyes. Smoking also increased odor and texture acceptability.     

Consumer perception of smoked Cheddar cheese

Consumer perception of smoked cheese was evaluated through focus groups, surveys, and central location testing. Three focus groups (n = 29) were conducted with consumers of smoked cheese. Subsequently, 2 online surveys were conducted. The purpose of the first survey (n = 1,195) was to understand types of smoked cheeses consumed and if consumers associated specific wood smokes with smoked cheese. Next, an adaptive choice-based conjoint (n = 367) was designed to evaluate consumer perception of different attributes of smoked cheese. Maximum difference scaling and familiarity questions were also included in the adaptive choice-based conjoint survey. Following the surveys, a central location test (n = 135) was conducted with cheeses smoked with 3 different woods at a low and high intensity (6 cheeses total). Hierarchical Bayesian estimation, 1-way ANOVA, agglomerative hierarchical clustering, and 2-way ANOVA (smoke type × intensity level) were used to interpret the collected data. Results from the focus groups indicated that smoked cheese was perceived as an artisan, high-end product and that appearance and price were strong purchase factors. In general, consumers were not aware of how smoked flavor was imparted to cheese, but when informed of the processes, they preferred cold-smoked cheese to the addition of liquid smoke flavor. Results from both surveys confirmed focus group observations. Consumers perceived flavor differences among different wood smokes and smoked products. Method of smoking, smoke intensity, type of wood, and type of cheese were the most important attributes for purchase of smoked cheese. When tasting, consumers differentiated smoke aroma and flavor among cheeses and preferred cherry wood smoked cheeses over apple wood or hickory smoked cheeses. Understanding consumer perceptions of smoked cheese will give insight into the desired experience that consumers expect when purchasing smoked cheese.     

Social proof in the supermarket: Promoting healthy choices under low self-control conditions

Under low self-control conditions, people often favor tempting but unhealthy food products. Instead of fighting against low self-control to reduce unhealthy food choices, we aim to demonstrate in a field study that heuristic decision tendencies can be exploited under these conditions. To do so a healthy product was associated with a social proof heuristic, referring to the tendency to adopt the option preferred by others. A healthy low-fat cheese was promoted with banners stating it was the most sold cheese in that supermarket. A state of low self-control was experimentally induced in the supermarket, and compared to a high self-control condition. Participants low in self-control were more likely to buy the low-fat cheese, when this product was associated with the social proof heuristic, compared to when it was not. This suggests that under low self-control conditions, presenting social proof cues may benefit healthy purchases.     

Food Safety Knowledge of Cheese Consumers

ABSTRACT:  The aim of this study was to evaluate habits and practices of cheese consumers toward their level of knowledge of food safety. A total of 1000 people were interviewed in several cities of the state of Rio de Janeiro, Brazil. Five hundred thirty-eight (53.8%) people consume cheese daily, while 318 (31.8%) and 144 (14.4%) consume cheese weekly and monthly, respectively. Five hundred twenty-two (52%) people reported its usage as an ingredient used in the preparation of other dishes, while 320 (32%) of the interviewed people consume cheese directly as a part of the diet. Typical Brazilian cheeses such as "Minas Frescal" and "Prato" cheese are preferred by 528 (52.8%) of the consumers. Of the total consumers, 764 (76.4%) purchase cheese from supermarkets, while 236 (23.6%) from open-air markets. Inspected cheese is purchased by 350 (35%) consumers, while 650 (65%) buy it without knowing if they were submitted to previous fiscalization. Four hundred thirty (43%) consumers do not know any disease transmitted by cheese that has not been inspected. Overall, educational campaigns must be developed by the Sanitary Surveillance and the Health Agencies to improve the knowledge of the consumer about food safety of cheeses.     

Hydrocolloid coating of cheeses

Semi-hard and dry white brined cheeses were coated with hydrocolloid films based on κ-carrageenan, alginate and gellan. The cheeses were immersed in the gum solution followed by cross-linking of the gum solution to produce a coated product. A few coating films were then dried by airflow to induce better adherence of the coating to the coated object. The coated cheeses were stored at 4°C and at a relative humidity of 73%. Weight loss, gloss, roughness of surface area, changes in mechanical properties versus time (i.e. stress and strain at failure, stiffness and elastic properties), peel-bond strength of the coating film from the cheese and sensory evaluation were studied for each coated system. For the semi-hard cheese, all kinds of coatings reduced weight loss during 46 days of storage. With regard to weight loss, no significant differences between the various coatings were found. The coating contributed to a better color and gloss. The roughness of the coated cheese decreased after coating, since surface ruggedness was filled in by the film. Advantages in the textural properties of the coated cheese were observed. Since the coated cheese lost less water by evaporation, a desirable softer and a less brittle texture was detected. The elastic properties of the cheeses were estimated by calculating the recoverable work (the ratio between recoverable and total compressive deformation) of coated and non-coated cheeses. This parameter appeared to decrease from 48 to 34% after 24 days of storage; no advantage of the coated cheese was observed. The peel-bond strength of the film based on alginate was 1 g force/cm. In the case of the dry white brined cheese, no deliberate drying of the coated film was performed. All coatings reduced weight loss of the cheese with a significant advantage of the κ-carrageenan-based coating. The coatings contributed to a lower reduction in pH, thus a higher-quality cheese was obtained. In addition, the coated cheeses were softer and less brittle when compared to the non-coated cheese. The percentage of recoverable work of cheeses did not change even after 24 days of storage. The coatings increased the gloss of the cheese fivefold in comparison to the non-coated cheese. In a sensory evaluation, the coated cheese was found to be advantageous over the non-coated system. In general, cheese coating based on hydrocolloid films improved textural and sensorial properties when compared to non-coated cheeses. The coatings did not influence the taste of white brined cheese, and the technology involved is simple and relatively inexpensive.     

市售天然成熟干酪滋味特征差异性研究

利用气相色谱质谱联用仪、氨基酸分析仪对8种典型天然成熟干酪的主要滋味成分进行分析,通过滋味活力值和感官评定阐明8种干酪间的滋味差异情况。结果表明:除了山羊乳干酪和布里干酪,其他6种干酪中游离氨基酸对滋味均有贡献,特征滋味氨基酸有缬氨酸和赖氨酸,即干酪共同带有苦味和甜味,而蓝纹干酪特征性氨基酸种类最丰富,滋味最强;8种干酪共检测到11种游离脂肪酸,共有的特征滋味脂肪酸为己酸、壬酸、癸酸、月桂酸和肉豆蔻酸。其中酸味程度最强的为艾达姆干酪,帕玛森干酪的醇厚感最强;8种干酪氯化钠含量明显高于阈值,可显著感受到咸味。经感官分析,干酪的滋味中咸味和鲜味比较突出,蓝纹干酪滋味强度最强。     

Ripened Semihard Cheese Covered with Lard and Dehydrated Rosemary (Rosmarinus officinalis L.) Leaves: Processing,Characterization, and Quality Traits

This study aimed to establish a manufacturing protocol and to characterize semihard cheese covered with lard and rosemary during ripening. After the manufacturing protocol was defined, the cheeses were produced with pasteurized and raw milk from Holstein cows, with and without (control) coating, and then ripened for 60 d. During this period the physicochemical properties, color, proteolysis, texture profile, and sensory acceptance were performed. The early‐ripening cheeses differed from the others in terms of color and moisture content. Multivariate statistical analysis separated chesses in groups differentiated by the effects of heat treatment of milk and ripening period. The ripened cheeses obtained from raw milk were sensorially more preferred. The coating gave the final products higher moisture content and favored color and texture characteristics. Consumer testing showed that the cheese obtained from raw milk and coated with lard and rosemary was the most preferred (acceptance of 82%) due to the specific coating of rosemary (aroma and flavor). This product has potential to add value and to diversify the production of semihard cheeses.     

基于电子舌技术不同超声处理时间的奶酪滋味区分

为探讨奶酪智能化品质评价的可行性,研究了电子舌专一选择型传感器检测5 种传统奶酪和2 种进口奶酪过程中的响应信号的特征。采用不同的模式识别方法对奶酪进行分类鉴别,通过主成分分析（principal component analysis,PCA）法、偏最小二乘法将感官评定值与响应值做相关性分析,并探讨了超声处理奶酪对电子舌响应信号的影响。结果表明：应用PCA能够大体反映各类样品的分类信息,PCA降维后的数据能够很好地反映原始数据信息。奶酪的前处理时间不同电子舌传感器的响应值也不同,本实验超声处理条件下对PCA辨别结果影响不大,UMS、GPS和SPS三根传感器与苦、咸味,以PC1为轴呈显著负相关,SWS与甜味以PC2为轴呈正相关。     

Dried Tomato‐Flavored Probiotic Cream Cheese with Lactobacillus paracasei

Abstract: A dried tomato‐flavored probiotic cream cheese (P) containing Lactobacillus paracasei Lpc‐37 was developed for the purpose of this study. The same product, but without probiotic addition (C) was used as control. Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris were used as lactic starter cultures. Chemical composition analyses and sensory tests were performed on days 1 and 7, respectively. Titratable acidity, pH value and L. paracasei population were determined every 7 d during the refrigerated storage (21 d) of the cream cheeses. The experiment and analyses were performed in triplicate, using standard methods. Probiotic population remained greater than 10⁷ CFU/g throughout the storage period, thereby characterizing the product as potentially probiotic. Cream cheeses C and P did not differ on the sensory tests, both obtaining good overall acceptance by the consumers, of which 82.6% stated that they certainly or probably would buy the product. Practical Application: Lactobacillus paracasei Lpc‐37 is a probiotic bacterium and clinical studies have shown that this microorganism beneficially affects its host. In general, dried tomato‐flavored products and cream cheese are products with good acceptance by the consumers. Thus, regular consumption of the probiotic cream cheese developed in this study may have positive effects on health and well being of people if incorporated into their diet.     

Potential use of homogenized whey protein dispersions and process modification for the manufacture of low fat and reduced fat cheddar type cheeses

Interest in cheese with lower fat than regular cheese has grown in recent years due to the changing eating habits of health conscious consumers, but production of such cheeses at low cost, without losing flavour and texture, is a challenge. In this study, modified processes were developed to manufacture low (˜20%) and reduced (˜15%) fat cheddar cheeses. Modifications of cooking time and temperature, along with changes in the amount of starter culture used and the addition of whey proteins, were studied. The results showed that low fat cheese could be manufactured with or without adding homogenized whey proteins, and reduced fat cheese could be manufactured with homogenized whey proteins. This finding reveals that it would be possible to manufacture these cheeses in an existing cheese plant, but that a homogenizer would be required if whey protein is to be added.