GC/MS and sensory analysis of volatiles from three cultivars of Capsicum

Development if healthy milk and yogurt products for reducing metabolic diseases using cyclodextrin and omega-3 fatty acids from fish oil

The food industry is constantly attempting to develop better products that will have a positive effect on health. Feiraco® and Clesa®, expressed their intention to create novel products using UNICLA® milk as a matrix to develop functional foods. In this respect, β-cyclodextrin (β-CD) at 1% was able to reduce the cholesterol concentration in Feiraco-UNICLA® milk products by around 87-85%. Products were fortified with omega-3 from fish oil with α- and β-CD acting as carriers. It was possible to add around 50% of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) Recommended Dietary Allowances (RDA), with a high diet proportion of fibre and similar organoleptic properties to commercial omega-3 products. 80% of a sensory panel found our formulations satisfactory. The final product was stable, and the bioaccessibilty of the fatty acids added to the milk was around 74%. These results as a whole satisfy the aid of Feiraco® and Clesa® to develop improved products.

Development of a Model System for Tasting Grain Varieties

This study investigated suitable approaches and effective applications for the evaluation of grain flavor differences among cultivars. A model system that helps to facilitate the characterization of flavors in grain varieties was developed using sorghum grain as a tool. Five different applications were initially used, including cooked grain, porridge, cookies, muffins, and extruded puffed snacks. Six highly trained sensory panelists participated in the project. The effectiveness of each application was determined based on the results of the attribute generation process and from panelist feedback. The results indicate that the combination of a cooked whole grain procedure and the use of flour made into cookies provides an effective and potent model for flavor characterization in both their grain form and as finished products. Both the recipes for the cooked grain and cookie applications effectively brought out the flavor characteristics of the grains as well as differentiated the flavor differences between grain cultivars. The developed model can be applied for the flavor evaluation of multiple grain types and can help researchers understand the flavor differences among grain cultivars. As a result, such knowledge will help to facilitate the selection of suitable products with favorable characteristics for specific applications as well as for selective breeding purposes.

HS-SPME comparative analysis of genotypic diversity in the volatile fraction and aroma-contributing compounds of Capsicum fruits from the annuum-chinense-frutescens complex

Volatile constituents of ripe fruits of 16 Capsicum accessions from the annuum-chinense-frutescens complex, with different aroma impressions and geographical origins, were isolated by headspace-solid phase microextraction (HS-SPME) and analyzed by gas chromatography-olfactometry-mass spectrometry (GC-sniffing port-MS). More than 300 individual compounds could be detected in the studied genotypes; most of them could be identified by comparing mass spectra and retention times with authentic reference substances or literature data. Esters and terpenoids were the main groups, although other minor compounds, such as nitrogen and sulfur compounds, phenol derivatives, norcarotenoids, lipoxygenase derivatives, carbonyls, alcohols, and other hydrocarbons, were also identified. The sniffing test revealed that the diversity of aromas found among the studied cultivars is due to qualitative and quantitative differences of, at least, 23 odor-contributing volatiles (OCVs). C. chinense, and C. frutescens accessions, with fruity/exotic aromas, were characterized by a high contribution of several esters and ionones and a low or nil contribution of green/vegetable OCVs. Different combinations of fruity/exotic and green/vegetable OCVs would explain the range of aroma impressions found among C. annuum accessions. Implications of these findings for breeding and phylogeny studies in Capsicum are also discussed.

Characterization of alkylmethoxypyrazines contributing to earthy/bell pepper flavor in farmstead cheddar cheese

Farmstead Cheddar cheeses with natural bandage wrappings have a distinctive flavor profile that is appealing to many consumers. An earthy/bell pepper (EBP) flavor has been previously recognized in some of these cheeses. This study characterized the alkylmethoxypyrazine compounds causing EBP flavor in Farmstead Cheddar cheeses. Eight cheeses were divided into inner, outer, rind, and wrapper sections, and tested for descriptive sensory and instrumental analyses. To assess reproducibility of EBP flavor, cheeses from the same facilities were purchased and tested after 6 and 12 mo. EBP flavor was detected in four out of 8 Farmstead Cheddar cheeses by a trained sensory panel. 2-sec-butyl-3-methoxypyrazine and 2-isopropyl-3-methoxypyrazine were identified as the main sources of EBP flavor in these cheeses by GC/O and GC/MS. In general, those alkylmethoxypyrazines were prevalent in the wrapper (106 to 730 ppb) and rind (39 to 444 ppb) sections of the cheeses. They were either not detected in inner and outer sections of the cheeses or were present at low concentrations. These results suggest that 2-sec-butyl-3-methoxypyrazine and 2-isopropyl-3-methoxypyrazine are formed near the surface of the cheeses and migrate into the cheese during ripening. Threshold values in water and whole milk were 1 and 16 ppt for 2-sec-butyl-3-methoxypyrazine, and 0.4 and 2.3 ppt for 2-isopropyl-3-methoxypyrazine, respectively. Sensory analysis of mild Cheddar cheese model systems confirmed that direct addition of those individual alkylmethoxypyrazines (0.4 to 20 ppb) resulted in EBP flavor.

Orthonasal and retronasal perception of some green leaf volatiles used in beverage flavors

Orthonasal perception of six green leaf volatiles (GLVs) classified only hexanal, (E)-2-hexenal, and (Z)-3-hexen-1-yl formate as green. (Z)-3-Hexen-1-yl hexanoate and (Z)-3-hexen-1-yl 3-methylbutyrate were more floral, and (Z)-3-hexen-1-yl acetate fell between the two groups. For retronasal perception, classification along a bipolar green-fruity scale is proposed for describing these GLVs. Data from grouping and dissimilarity tests as well as from sensory profiling show green character for these compounds in standard beverage bases having low Brix or high acidity. As the Brix value increases (or acidity decreases) within the limits encountered in commercial beverages, the character becomes fruity. Several tastant-dependent changes in intensity scores for retronasal descriptors were shown to occur for mixtures of GLVs. The GLVs did not affect intensity scores for gustatory descriptors.

Comprehensive two-dimensional gas chromatography/mass spectrometric analysis of pepper volatiles

The headspace compositions of 13 pepper and peppercorn samples of different species, colloquially also referred to as pepper, were analyzed, and more than 300 compounds were tentatively characterized by means of comprehensive two-dimensional gas chromatography in tandem with flame ionization detection, quadrupole mass spectrometric detection and time-of-flight mass spectrometric detection (GC x GC-FID, GC x GC/qMS and GC x GC/TOFMS, respectively). The analysis of volatile organic compounds (VOCs) was performed after solid-phase microextraction (SPME) using a 75-microm PDMS/DVB fibre. Fingerprint comparison between the three techniques permitted peaks to be assigned in the GC x GC-FID experiment based on the analogous MS analysis, taking into account retention shifts arising from method variations. When using GC x GC/TOFMS, about five times more peaks were identified than in GC x GC/qMS. Retention indices for all peaks were calculated in the bi-dimensional column set comprising of a 5% phenyl polysilphenylene-siloxane primary column and a polyethylene glycol second column. The spectra obtained by both mass detection techniques (qMS and TOFMS) give very similar results when spectral library searching was performed. The majority of the identified compounds eluted as pure components as a result of high-resolution GC x GC separations, which significantly reduces co-elution, and therefore increases the likelihood that pure spectra can be obtained. The differences between TOFMS and qMS (in fast scanning mode) spectra were generally small. Whilst spectral quality and relative ion ratios across a narrow peak (e.g. w(b) approximately 100-150 ms) do vary more for the fast peaks obtained in GC x GC/qMS operation, than with TOFMS, in general adequate spectral matching with the library can be achieved.

Capsicum--production, technology, chemistry, and quality. Part IV. Evaluation of quality

Capsicum fruits are popular worldwide and are used in the cuisines of both the developing and the developed countries. With its different varieties, forms, and uses, the spice capsicum contributes to the entire gamut of sensory experience--color as finely ground paprika powder or extract in sausages, goulash, cheese, and snacks; both pungency and color as the many varieties of chillies used in Mexican, African, Indian, and southeast Asian cuisines; color, aroma, and mild pungency as the fresh green chillies used in many of the growing countries; and appearance, color, aroma, and texture as fresh fruit in salads and as a pickled and canned product. In three earlier parts in this series, the varieties, cultivation, and primary processing; the processed products, world production, and trade; and the chemistry of the color, aroma, and pungency stimuli have been reviewed. In this part, the evaluation of quality through instrumental determination of the causal components and the sensory evaluation of color, aroma, and pungency are discussed. Several methods for quantitative determination of the stimuli and the sensory evaluation of the responses to the stimuli are reviewed. The problems of sensory evaluation of color, aroma, and pungency, the dominant attributes for validation of the instrumentally determined values for carotenoids, volatiles, or particular fractions, and total and individual capsaicinoids are specifically discussed. Summarized details of selected instrumental methods for evaluating the stimuli, which are either validated by correlation to sensorily perceived responses or to adopted standards, are given along with representative data obtained for discussing the adequacy and reliability of the methods. Pungency as a specific gustatory perception and the many methods proposed to evaluate this quality are discussed. A recommended objective procedure for obtaining reproducible values is discussed, and a method for relating different panel results is shown. With such a method, highly significant correlations have been shown between estimated total capsaicinoids and the determined pungency. The estimation of total capsaicinoids by any simple, reliable method is shown to be adequate for quality control of pungency of Capsicum fruits.

Capsicum--production, technology, chemistry, and quality. Part III. Chemistry of the color, aroma, and pungency stimuli

The spice capsicum, the fruits of the genus Capsicum (Family Solanaceae), is a very popular food additive in many parts of the world, valued for the important sensory attributes of color, pungency, and aroma. A large number of varieties are widely cultivated and traded. The characteristic carotenoids of the bright red paprika and cayenne-type chillies, the high character impact aroma stimuli, the methoxy pyrazine of green bell capsicum, the esters of ripe tabasco and the highly potent pungency stimuli, and the capsaicinoids of African and other Asian varieties of chillies, have been of great interest to chemists and biochemists. Research workers in other disciplines such as genetics and breeding, agriculture, and technology have been interested in this spice to develop new varieties with combinations of different optimal levels of the stimuli for the sensory attributes and to maximize production of storable products for specific end uses. Physiologists have been intensely studying the action of the highly potent pungency stimuli and social psychologists the curious aspect of growing acceptance and preference for the initially unacceptable pungency sensation. In the sequential review of all these aspects of the fruit spice Capsicum, the earlier two parts covered history, botany, cultivation and primary processing, and processed products, standards, world production, and trade. In Part III, the chemistry, the compositional variations, synthesis and biosynthesis of the functional components, the carotenoids, the volatiles, and the capsaicinoids are comprehensively reviewed.