Taste active compounds in a goat cheese water-soluble extract. 1. Development and sensory validation of a model water-soluble extract

Characterization of Bitter Compounds in Shaoxing Huangjiu by Quantitative Measurements, Taste Recombination, and Omission Experiments

Excessive and uncoordinated bitterness of Shaoxing Huangjiu, a traditional Chinese rice wine, reduces its acceptance by consumers. To determine the compounds responsible for this bitterness, gas chromatography-mass spectrometry and high-performance liquid chromatography were performed on four types of Shaoxing Huangjiu (Yuanhong, Huadiao, Shanniang, and Xiangxue wine) for targeted quantitation of candidate compounds known to contribute to bitterness. Calculations of dose-over-threshold factors revealed that isoamyl alcohol, 1-hexanol, phenylethanol, ethyl butyrate, ethyl lactate, furfural, histidine, and arginine were important bitter compounds. Taste recombination experiments demonstrated that a recombination model constructed using the screened known bitter compounds showed good similarity with the original sample in bitter taste. Furthermore, omission experiments revealed that isobutanol, isoamyl alcohol, 1-hexanol, phenylethanol, ethyl acetate, ethyl butyrate, ethyl lactate, furfural, arginine, and valine were the compounds affecting the bitter taste perception. This study provides a certain guiding effect on the bitterness control and taste improvement of Shaoxing Huangjiu.

Effect of the Ripening Period and Intravarietal Comparison on Chemical, Textural and Sensorial Characteristics of Palmero (PDO) Goat Cheese

Palmero cheese is an artisanal dairy product from the Canary Islands (Spain), awarded with the Protected Denomination of Origin (PDO) from the European Union. It is made with raw milk from the Palmera dairy goat on La Palma island. The aim of this research covered the physicochemical and sensorial characterization of Palmero cheese along 90 days of ripening. Palmero cheeses from four cheese factories were analysed for basic physicochemical parameters, instrumental texture and colour and sensorial profile. Most of the basic composition and the texture and colour attributes of Palmero cheese changed significantly along maturation. During the 90 days of ripening an increase in hardness, fracturability and gumminess (p < 0.001) occurred while elasticity decreased simultaneously (p < 0.001). The internal lightness value decreased significantly (p < 0.001), while yellowness increased (p < 0.001) during cheese ripening. Ripening time affected six of nine sensorial texture characteristics and the entire odour and flavour parameters analysed (p < 0.001). Regarding to intravarietal comparison, in general, cheeses from the four dairy plants showed similar composition although significant differences were detected on textural, colour and sensorial characteristics.

Sensory-Guided Analysis of Key Taste-Active Compounds in Pufferfish (Takifugu obscurus)

To investigate key taste-active components in Takifugu obscurus, 28 putative taste compounds in cooked muscle of T. obscurus were quantitatively analyzed and the pivotal components were identified by taste reconstitution, omission, and addition tests. Moreover, the role of flavor peptides in the overall taste profile of T. obscurus was evaluated. Sensory evaluation revealed that glutamic acid, serine, proline, arginine, lysine, adenosine 5'-monophosphate, inosine 5'-monophosphate (IMP), succinic acid, sodium, potassium, phosphates, and chlorides were the core taste-active contributors to T. obscurus. Besides glutamic acid, IMP, succinic acid, and potassium, the characteristic T. obscurus-like umami and kokumi profiles were induced by adding flavor peptides, among which Pro-Val-Ala-Arg-Met-Cys-Arg and Tyr-Gly-Gly-Thr-Pro-Pro-Phe-Val were identified as key substances on the basis of the addition test and dose-response analysis. The present data may help to reveal the secret of the delicious taste of T. obscurus and provide the basis for the development of deeper flavor analysis of pufferfish.

Sire breed effect on beef longissimus mineral concentrations and their relationships with carcass and palatability traits

The objective of this study was to evaluate sire breed effect on mineral concentration in beef longissimus thoracis (LT) and investigate the correlations between beef mineral concentrations and carcass and palatability traits. Steer progeny (N=246) from the Germplasm Evaluation project-Cycle VIII were used in this study. In addition to carcass traits, LT was evaluated for mineral concentrations, Warner-Bratzler shear force, and palatability traits. A mixed linear model estimated breed effects on mineral concentrations. No significant sire breed (P≥0.43) or dam breed (P≥0.20) effects were identified for mineral concentrations. Pearson correlation coefficients were calculated among mineral concentrations, carcass, and sensory traits. Zinc concentration was positively correlated (P≤0.05) with total iron (r=0.14), heme iron (r=0.13), and magnesium (r=0.19). Significant (P<0.05) correlations were identified between non-heme or heme iron and most traits in this study. Magnesium concentration was correlated with all carcass and palatability traits.

Quantitative studies and taste re-engineering experiments toward the decoding of the nonvolatile sensometabolome of Gouda cheese

The first comprehensive quantitative determination of 49 putative taste-active metabolites and mineral salts in 4- and 44-week-ripened Gouda cheese, respectively, has been performed; the ranking of these compounds in their sensory impact based on dose-over-threshold (DoT) factors, followed by the confirmation of their sensory relevance by taste reconstruction and omission experiments enabled the decoding of the nonvolatile sensometabolome of Gouda cheese. The bitterness of the cheese matured for 44 weeks was found to be induced by CaCl2 and MgCl2, as well as various bitter-tasting free amino acids, whereas bitter peptides were found to influence more the bitterness quality rather than the bitter intensity of the cheese. The DoT factors determined for the individual bitter peptides gave strong evidence that their sensory contribution is mainly due to the decapeptide YPFPGPIHNS and the nonapeptides YPFPGPIPN and YPFPGPIHN, assigned to the casein sequences beta-CN(60-69) and beta-CN(60-68), respectively, as well as the tetrapeptide LPQE released from alphas1-CN(11-14). Lactic acid and hydrogen phosphate were identified to play the key role for the sourness of Gouda cheese, whereas umami taste was found to be due to monosodium L-glutamate and sodium lactate. Moreover, saltiness was induced by sodium chloride and sodium phosphate and was demonstrated to be significantly enhanced by L-arginine.

Sensomics mapping and identification of the key bitter metabolites in Gouda cheese

Application of a sensomics approach on the water-soluble extract of a matured Gouda cheese including gel permeation chromatography, ultrafiltration, solid phase extraction, preparative RP-HPLC, and HILIC combined with analytical sensory tools enabled the comprehensive mapping of bitter-tasting metabolites. LC-MS-TOF and LC-MS/MS, independent synthesis, and sensory analysis revealed the identification of a total of 16 bitter peptides formed by proteolysis of caseins. Eleven previously unreported bitter peptides were aligned to beta-casein, among which 6 peptides were released from the sequence beta-CN(57-69) of the N terminus of beta-casein and 2 peptides originated from the C-terminal sequence beta-CN(198-206). The other peptides were liberated from miscellaneous regions of beta-casein, namely, beta-CN(22-28), beta-CN(74-86), beta-CN(74-77), and beta-CN(135-138), respectively. Six peptides were found to originate from alpha(s1)-casein and were shown to have the sequences alpha(s1)-CN(11-14), alpha(s1)-CN(56-60), alpha(s1)-CN(70/71-74), alpha(s1)-CN(110/111-114), and alpha(s1)-CN(135-136). Sensory evaluation of the purified, synthesized peptides revealed that 12 of these peptides showed pronounced bitter taste with recognition thresholds between 0.05 and 6.0 mmol/L. Among these peptides, the decapeptide YPFPGPIHNS exhibited a caffeine-like bitter taste quality at the lowest threshold concentration of 0.05 mmol/L.

Alternatives for Improving Physical, Chemical, and Sensory Characteristics of Goat Cheeses: The Use of Arid-Land Forages in the Diet

To establish the effect of an alternative diet on the quality of Majorero cheese, the basic physicochemical parameters, fatty acid profile, and sensory characteristics were studied. Two groups of 20 Majorero goats were fed 2 different diets: a forage diet (DF), which had a high ratio of long fiber to concentrates (65:35), and a concentrate diet (DC), with a low ratio of long fiber to concentrates (35:65). The DF dietary fiber was supplied by native forages adapted to arid land. A total of 42 Majorero goat cheeses were used for this study: 21 in the DF group and 21 in the DC group. Seven cheeses from each group were tested after 2, 15, and 60 d of ripening. The milk produced by goats fed the DF diet had a higher fat concentration. No significant differences were observed in the milk fatty acid profile. The diet affected the chemical composition of the cheese in pH and fat content, and fat was significantly higher in cheeses made from DF milk than those from DC milk. Dietary characteristics had important effects on the medium-chain fatty acid composition (C6 to C14) of the cheese fat, giving DF cheeses the specific goat's milk flavor that is sought after for this type of cheese. The fatty acid composition (%) differed substantially among different ripening times. The DF cheeses were more appreciated by the panelists, as they had a greater variety of odors and flavors than the DC cheeses. The DF hard cheeses were described as having vegetable and fruity tones as well as tones of hay and dried fruit.

Chromatography in authenticity and traceability tests of vegetable oils and dairy products: a review

The new applications of various chromatographic techniques such as gas-liquid chromatography, high-performance liquid chromatography and electrophoretic methods employed for the analysis in macro- and micro-components in vegetable oils and dairy products are compiled and critically evaluated. The employment of these methods for authenticity tests and traceability is discussed.