The effect of application of cold natural smoke on the ripening of Cheddar cheese

Development of a Novel Flavored Goat Cheese with Gentiana lutea Rhizomes

Gentiana lutea rhizomes, generally used as a bittering agent in food, were harvested from two geographical sites (Massif Central: MC and Jura: J) to evaluate their potential use in the flavoring step during goat cheesemaking. Gentian flavored goat cheeses (MCGC and JGC) were elaborated by a one-night immersion of unflavored goat cheeses (CGC) into gentian-infused whey. The impregnation of gentian in goat cheeses was evaluated by chemical and sensory analysis. The chemical composition of cheeses was analyzed by HS-SPME-GC-MS (Head-Space-Solid Phase MicroExtraction-Gas Chromatography-Mass Spectrometry) for volatile compounds (alcohols, ketones, aldehydes, esters, alkenes, alkanes, acids, terpenes) and UHPLC-DAD (Ultra High-Performance Liquid Chromatography-Diode Array Detector) for gentian bitter compounds (seco-iridoids). The sensory analysis consisted of a bitterness rating and a free description of cheeses by 17 trained panelists. Results of the study highlighted that unflavored goat cheeses presented higher unpleasant notes (goaty and lactic whey) and higher amounts of hexanoic acid and toluene compared to gentian flavored goat cheeses. The bitterness of gentian flavored goat cheeses was higher compared to unflavored cheeses and could be explained by loganic acid transfer from yellow gentian to flavored cheeses. Other free descriptors of gentian flavored goat cheeses revealed more complex notes (herbal, vegetal, floral, sweet, spicy and creamy) and higher relative amounts of volatile compounds such as 3-methyl butanoic acid, 2-methyl propanoic acid, 4-methyl decane, 2,3-butanediol, ethanol, diacetyl, methyl acetate and 2-phenylethyl acetate, compared to unflavored cheeses. Phenylethyl acetate was the only volatile compound that enabled differentiation of gentian origin on gentian flavored goat cheeses. Gentian rhizomes could be considered a promising flavoring agent contributing to the olfactive and gustative complexity of flavored goat cheeses and the reduction of their goaty perceptions.

Identification of aroma-active compounds in Cheddar cheese imparted by wood smoke

Cheddar cheese is the most popular cheese in the United States, and the demand for specialty categories of cheese, such as smoked cheese, are rising. The objective of this study was to characterize the flavor differences among Cheddar cheeses smoked with hickory, cherry, or apple woods, and to identify important aroma-active compounds contributing to these differences. First, the aroma-active compound profiles of hickory, cherry, and apple wood smokes were analyzed by solid-phase microextraction (SPME) gas chromatography-olfactometry (GCO) and gas chromatography-mass spectrometry (GC-MS). Subsequently, commercial Cheddar cheeses smoked with hickory, cherry, or apple woods, as well as an unsmoked control, were evaluated by a trained sensory panel and by SPME GCO and GC-MS to identify aroma-active compounds. Selected compounds were quantified with external standard curves. Seventy-eight aroma-active compounds were identified in wood smokes. Compounds included phenolics, carbonyls, and furans. The trained panel identified distinct sensory attributes and intensities among the 3 cheeses exposed to different wood smokes (P < 0.05). Hickory smoked cheeses had the highest intensities of flavors associated with characteristic "smokiness" including smoke aroma, overall smoke flavor intensity, and meaty, smoky flavor. Cherry wood smoked cheeses were distinguished by the presence of a fruity flavor. Apple wood smoked cheeses were characterized by the presence of a waxy, green flavor. Ninety-nine aroma-active compounds were identified in smoked cheeses. Phenol, guaiacol, 4-methylguaiacol, and syringol were identified as the most important compounds contributing to characteristic "smokiness." Benzyl alcohol contributed to the fruity flavor in cherry wood smoked cheeses, and 2-methyl-2-butenal and 2-ethylfuran were responsible for the waxy, green flavor identified in apple wood smoked cheeses. These smoke flavor compounds, in addition to diacetyl and acetoin, were deemed important to the flavor of cheeses in this study. Results from this study identified volatile aroma-active compounds contributing to differences in sensory perception among Cheddar cheeses smoked with different wood sources.

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.

Chemical changes that predispose smoked Cheddar cheese to calcium lactate crystallization

We have observed a high incidence of calcium lactate surface crystals on naturally smoked Cheddar cheese in the retail marketplace. The objective of this study was to identify chemical changes that may occur during natural smoking that render Cheddar cheese more susceptible to calcium lactate crystal formation. Nine random-weight (approximately 300 g) retail-packaged samples of smoked Cheddar cheese were obtained from a commercial manufacturer immediately after the samples were smoked for about 6 h at 20 degrees C in a commercial smokehouse. Three similarly sized samples that originated from the same 19.1-kg block of cheese and that were not smoked were also obtained. Within 2 d after smoking, 3 smoked and 3 control (not smoked) samples were sectioned into 5 subsamples at different depths representing 0 to 2, 2 to 4, 4 to 6, 6 to 8, and 8 to 10 mm from the cheese surface. Six additional smoked cheese samples were similarly sectioned at 4 wk and again at 10 wk of storage at 5 degrees C. Sample sections were analyzed for moisture, L(+) and D(-) lactate, pH, and water-soluble calcium. The effects of treatment (smoked, control), depth from cheese surface, and their interactions were analyzed by ANOVA according to a repeated measures design with 2 within-subject variables. Smoked samples contained significantly lower moisture and lower pH, and higher total lactate-in-moisture (TLIM) and water-soluble calcium-in-moisture (WSCIM) than control cheeses. Smoked samples also contained significant gradients of moisture, pH, TLIM, and WSCIM, with lower moisture and pH, and higher TLIM and WSCIM, occurring at the cheese surface. Gradients of moisture were still present in smoked samples at 4 and 10 wk of storage. In contrast, the pH, TLIM, and WSCIM equilibrated and showed no gradients at 4 and 10 wk. The results indicate that calcium and lactate in the serum phase of the cheese were elevated because of smoking, especially at the cheese surface immediately after smoking treatment, which presumably predisposes the smoked cheeses to increased susceptibility to calcium lactate surface crystallization.

ADSA Foundation Scholar Award: Defining Dairy Flavors

Production and consumption of dairy foods continue to increase annually. Further, new ingredient applications for dairy foods continue to expand. With continued production and consumption, there is also increased competition. Increased competition exists regionally, nationally, and globally. Processors as well as product developers must find ways to maximize existing markets and expand into new markets. A consistent high quality product is necessary to maintain competitiveness. Although microbial safety and stability are key ways to define quality, flavor is one method of defining quality that is often assumed or overlooked. The aggressive and competitive nature of today's market demands more precise and powerful tools for defining flavor and flavor quality. Traditional as well as more recent methods for evaluating dairy flavor are reviewed. The application of defining sensory flavors to fundamental research on flavor chemistry, product understanding, and effective marketing is addressed.