Sensory descriptive analysis and consumer acceptability of selected Swiss goat and sheep cheeses

Consumer acceptance for sheep milk-based yogurt-Evidence from a large sample of Italian consumers

Testing consumer acceptance for a new product, such as the sheep milk-based yogurt, provides a measure of its market success, thus it informs producers on the effectiveness of their decision to transform sheep milk into yogurt to increase their revenues. This work explores to what extent consumers accept sheep milk-based yogurt and tests the role of personal-related factors and product-related features on shaping its acceptance. The study collects data from a representative sample of Italian yogurt consumers, and data are then analyzed via a logistic regression. Results show that male, highly educated, and high-income consumers are more likely than others to accept sheep milk-based yogurt. Findings suggest that consumers' food neophobia and variety seeking traits play a pivotal role in affecting consumer acceptance. Lastly, interest in nutritional and health-related yogurt features increases the probability of accepting sheep milk-based yogurt. Thus, sheep milk-based yogurt should be targeted at high-end male consumers and those interested in nutritional and health-related aspects of yogurt. Informing consumers about the sheep milk yogurt properties may further increase its acceptance and curb food neophobia, which we found to be one of the main barriers for the product acceptance. Future studies will explore consumer acceptance by using a real product and taste experiments.

The influence of the texture and color of goat’s salad cheese on the emotional reactions of consumers compared to cow’s milk cheese and Feta cheese

In this study, the sensory and mechanical aspects of the texture of goat’s milk salad cheese were correlated with the emotional profiles of consumers. Using descriptive sensory analysis and instrumental assessment, the texture profile of goat’s milk salad cheese was compared to cow’s milk salad cheese and Feta cheese. Texture measurements confirmed that goat’s cheese compared to cow’s cheese had more softness and less hardness, and Feta cheese had the highest whiteness index compared to the other cheeses. Goat’s milk salad cheese was much less acceptable to consumers compared to cow’s milk cheese and Feta cheese. Consumers also indicated that the hardness of goat’s cheese was lower than that of cow’s cheese and Feta cheese. A reduction in “stickiness” in comparison with cow’s cheese was also reported; however, it was much higher than that for Feta cheese. The “fracturability” and “graininess” of goat’s cheese was similar to cow’s cheese. Emotional profile analysis showed that goat’s cheese evokes mainly negative emotions. Consumers indicated only one positive emotion in the case of this cheese, which was “healthy”. The most frequently mentioned emotions after the consumption of goat’s cheese were “upset”, “disgusted” and “worried”. Many consumers also indicated “disappointed” and “angry”, which did not occur after the consumption of cow’s cheese. This research shows how important it is to combine several analyses and techniques when evaluating dairy products, including salad cheeses. It is also important that consumer research is enriched by emotional profiling.

Graphical abstract

Transmission Scenarios of Listeria monocytogenes on Small Ruminant On-Farm Dairies

Listeria monocytogenes can cause severe foodborne infections in humans and invasive diseases in different animal species, especially in small ruminants. Infection of sheep and goats can occur via contaminated feed or through the teat canal. Both infection pathways result in direct (e.g., raw milk from an infected udder or fresh cheese produced from such milk) or indirect exposure of consumers. The majority of dairy farmers produces a high-risk product, namely fresh cheese made from raw ewe's and goat's milk. This, and the fact that L. monocytogenes has an extraordinary viability, poses a significant challenge to on-farm dairies. Yet, surprisingly, almost no scientific studies have been conducted dealing with the hygiene and food safety aspects of directly marketed dairy products. L. monocytogenes prevalence studies on small ruminant on-farm dairies are especially limited. Therefore, it was our aim to focus on three main transmission scenarios of this important major foodborne pathogen: (i) the impact of caprine and ovine listerial mastitis; (ii) the significance of clinical listeriosis and outbreak scenarios; and (iii) the impact of farm management and feeding practices.

Development of "Quadrello di Ovino", a Novel Fresh Ewe's Cheese

This work was performed to produce a new soft ewe's milk cheese, namely "Quadrello di ovino" (QdO) cheese, to enlarge ewe's dairy product portfolio of South Italy, barely limited to Pecorino cheese typology. Cheese making was performed applying the technology for "Crescenza" cheese typology with some modifications. In particular, pasteurized ewes' milk was inoculated with two commercial starter formulations (SF1 and SF2) of Streptococcus thermophilus to obtain two different productions (QdO-P1 and QdO-P2, respectively). Plate counts demonstrated the ability of both starter formulations to drive the fermentation process, since S. thermophilus counts reached 109 CFU/g in both productions. Generally, the two starter formulations did not affect the chemical composition of QdO cheeses that contained, on average, 64.08% dry matter of which approximately 54.99% were fats and 36.39% proteins. Among chemical parameters, significant differences were registered for secondary lipid oxidation state (significantly lower for QdO-P2), fatty acids and volatile organic compounds (VOCs). However, the differences registered among cheese VOCs from were not perceived by the panelists who recognized both cheese productions highly similar, although QdO-P2 cheeses were mostly appreciated by the judges. This study allowed to produce a novel fresh ovine cheese with specific chemical and sensorial characteristics well appreciated by consumers.

Relationship between Sensory Attributes, (Dis) Liking and Volatile Organic Composition of Gorgonzola PDO Cheese

Blue-veined cheese tends to polarize the consumers' affective responses due to its strong flavor. This study aims to: (i) explore the consumers' sensory perceptions and liking of Gorgonzola PDO cheese; (ii) identify the sensory drivers of acceptance for Gorgonzola in the function of the cheese style; (iii) characterize them by the volatile organic compounds (VOCs); and (iv) explore the relationships of the VOCs with sensory perception and liking. Six samples of Gorgonzola cheese differing in style (sweet vs. piquant), aging time (70-95 days), and production process (artisanal vs. industrial) were evaluated by 358 subjects (46% males, 18-77 years) using liking and Rate-All-That-Apply (RATA) tests. The cheese VOCs were measured by SPME/GC-MS. Liking was significantly higher for the sweet cheese than for the piquant cheese and for the artisanal cheese than for the industrial samples. Penalty Analysis showed that 'creamy', 'sweet', 'nutty', and 'salty' were significant drivers of liking while the 'soapy' and 'ammonia' flavors turned out to be drivers of disliking. Fifty-three VOCs were identified. Regression models revealed the significant highest associations between the VOCs and 'ammonia', 'pungent', 'soapy', and 'moldy' flavors. A good association was also found with the consumers' liking. The identification of the sensory drivers of (dis) liking and their relationship with the VOCs of Gorgonzola opens up a new understanding of the consumers' blue-veined cheese preferences.

High Heat Treatment of Goat Cheese Milk. The Effect on Sensory Profile, Consumer Acceptance and Microstructure of Cheese

Goat cheeses from high heat treated milk (HHTM: 80 °C/5 min (E1) and 90 °C/5 min (E2)), could be regarded as new products, compared to their analogues made from commonly pasteurized milk (65 °C/30 min (C)). Descriptive analysis and consumer tests with a hedonic scale and JAR scale were part of the product development process. The use of scanning electron microscopy enabled deeper insight into the flavor and texture of the cheeses. In all cheese variants, goaty flavor was mildly pronounced. Young HHTM cheeses also had a pronounced whey and cooked/milky flavor. Consumers found such flavor ‘too intensive’. Unlike the control variant, HHTM cheeses were not described as ‘too hard’. Such improvement in texture was found to be a result of fine, highly branched microstructure, sustained over the course of ripening time and highly incorporated milk fat globules inside the cheese mass. Cluster analysis showed that the largest group of consumers (47.5%) preferred E2 cheese. Although consumers found that most of the cheeses were ‘too salty’, this excess did not decrease their overall acceptance. Neither microstructure analysis nor descriptive sensory analysis of goat white brined cheeses produced from high heat treated milk has been done before.

Raw Goat's Milk, Fresh and Soft Cheeses as a Potential Source of Encephalitozoon cuniculi

The aim of this work was to evaluate the effect of pasteurization and coagulation during goat cheese production on the infectivity of Encephalitozoon cuniculi spores for immunodeficient (SCID, CD4^-/-, and CD8^-/-) and immunocompetent (BALB/c and C57BL/6) mice. Goat milk and fecal samples were screened for the presence and quantity of microsporidial DNA using molecular methods. Experimentally produced cheese from E. cuniculi-enriched goat milk or goat cheese purchased from retail producers was fed with experimental mice susceptible to E. cuniculi infection. The mice were sacrificed in the presumed acute phase of infection and samples of their tissues were subject to molecular detection of specific E. cuniculi DNA. Specific DNA of E. cuniculi genotype II was detected in feces and milk of three out of 99 goats kept on 6 farms in the Czech Republic. Under experimental conditions, spores of E. cuniculi genotype II remained viable in artificially enriched fresh cheese and were able to cause infection in laboratory mice. E. cuniculi genotype I and II DNA were detected in eight of the nine goat cheeses purchased from various producers/breeders in the Czech Republic and these cheeses were able to develop infection in both immunodeficient and immunocompetent mice. The results of these experiments showed that spores of E. cuniculi genotype I and II are able to remain viable after cheese processing and thus fresh and soft cheeses should be considered a potential source of microsporidia.

Chemical and fatty acid composition of Manchego type and Panela cheeses manufactured from either hair sheep milk or cow milk

This study compared the chemical composition and fatty acid (FA) profile of Manchego type cheese and Panela cheese made from hair sheep milk and compared these with both types of cheese manufactured with cow milk as a reference. In addition, this study aimed to determine differences in sensory characteristics between Manchego type cheeses manufactured with either hair sheep milk or cow milk. A total of 25 and 14 Manchego type cheeses from hair sheep milk and cow milk were manufactured, respectively. In addition, 30 and 15 Panela cheeses from hair sheep milk and cow milk were manufactured, respectively. The chemical composition and FA profile were determined in all cheeses. In addition, a sensory analysis was performed in Manchego type cheeses manufactured from either hair sheep milk or cow milk. Moisture content was lower in Manchego type cheeses (37.5 ± 1.26 and 37.5 ± 1.26 g/100 g in cheeses manufactured from hair sheep milk and cow milk, respectively) than in Panela cheeses (54.0 ± 1.26 and 56.1 ± 1.26 g/100 g in cheeses manufactured from hair sheep milk and cow milk, respectively). Ash, protein, and sodium contents were higher in Manchego type cheeses than in Panela cheeses. Manchego type cheese manufactured from hair sheep milk contained more C4:0, C6:0, C8:0, C10:0, C12:0, C14:0, C18:2 cis-9,cis-12, total saturated FA, total short-chain FA, total medium-chain FA, total polyunsaturated FA, and de novo FA than Manchego type cheeses from cow milk. Total content of short-chain FA was higher in hair sheep cheeses (24.4 ± 1.30 and 19.6 ± 1.30 g/100 g in Manchego type and Panela cheeses, respectively) than in cow cheeses (8.89 ± 1.30 and 8.26 ± 1.30 g/100 g in Manchego type and Panela cheeses, respectively). Manchego type cheeses from hair sheep milk obtained higher scores for odor (7.05), texture (6.82), flavor (7.16), and overall acceptance (7.16) compared with those made from cow milk (6.37, 6.12, 6.17, and 6.83, respectively). In conclusion, both Manchego type cheese and Panela cheese manufactured with hair sheep milk had a similar chemical composition and contained higher levels of short-chain FA, total polyunsaturated FA, and de novo FA than those manufactured with cow milk.

Characterization of the key aroma compounds in Yunnan goat milk cake using a sensory-directed flavor analysis

To identify the key aroma compounds in Yunnan goat milk cake, seven varieties of milk cake samples were subjected to sensory analysis and gas chromatography-mass spectrometry (GC-MS), gas chromatography-olfactometry (GC-O), aroma recombination, omission, and addition tests. The GC-MS results revealed 53 compounds with aroma characteristics in all the samples. A further comparison of odor activity values and aroma intensities (AI) revealed 25 of these compounds as the initial key aroma compounds. The contributions of these key aroma compounds to the sensory attributes were determined using a partial least squares regression. Of these compounds, 2-heptanone and 2-nonanone were closely related to the "milky" and "cheesy" attributes and were highly abundant in the samples from Kunming. Fatty acids, including butanoic acid, hexanoic acid, octanoic acid, and decanoic acid, were the most abundant compounds detected in the milk cakes. These fatty acids were closely related to the "rancid" and "animalic (goat)" attributes and were largely detected in the samples from Dali Dengchuan and Dali Xiaguan. Sensory-directed aroma recombination, omission, and addition tests further validated the important contributions of ethyl butyrate, benzaldehyde, 3-methyl-1-butanol, 2-heptanone, hexanoic acid, and octanoic acid to the overall sensory properties. Moreover, ethyl butyrate, benzaldehyde, and 2-heptanone, when added, had evident inhibitory or masking effects on the AI of "sour," "rancid," and "animalic (goat)" attributes. PRACTICAL APPLICATION: Goat milk cake is a popular acid-curd cheese in Yunnan, China, however, our limited knowledge to its key aroma compounds restricts its development and industrial production. In this study, a sensory-directed flavor analysis was used to characterized the key aroma compounds of Yunnan goat milk cake, which will help to enhance our understanding on the flavor profile of Yunnan goat milk cake and provide a reference for optimizing the flavor feature and organoleptic quality of this fresh goat cheese.

Sensory profile of sheep cheeses during a six-month storage period as evaluated by consumers

Over the past decade, the use of check-all-that-apply questions has become an easier and faster alternative to traditional sensory profiles using trained assessors, allowing the characterisation of a product by consumers. In this study, 65 consumers evaluated the acceptability of six artisan Uruguayan sheep cheese samples during a six-month storage period, providing a descriptive profile using a check-all-that-apply questionnaire consisting of 32 sensory and non-sensory terms. Although the acceptability of five of the six samples was not modified during storage, the consumers were able to perceive changes in the texture and flavour of products, providing a sensory profile of the cheeses. The categories s trange flavour, animal odour, strange odour, bitter and acidic were associated with negative terms such as bad quality and unpleasant flavour, whereas salty and tasty appeared to be related to positive terms including good quality, pleasant flavour and delicious. Therefore, for the Uruguayan consumer, preference for this type of product appears to be mainly conditioned by the flavour perceived in these cheeses, rather than their texture attributes.