Impact of salt reduction on the instrumental and sensory flavor profile of vegetable soup

The flavor of two vegetable soups, a commercial regular salt soup (0.93% NaCl) and its reformulated low salt equivalent (0.45% NaCl), were profiled using flavor profile analysis and solid-phase microextraction (SPME) coupled with gas chromatography mass spectrometry (GC-MS) instrumental analysis. Generalized procrustes analysis (GPA) of the sensory data revealed that the regular salt soup was strongly correlated with the attributes “salt flavor”, “yellow color”, “carrot aroma” and “overall flavor”. Reducing the salt content of the low salt soup had a significant effect on the attributes “green color”, “sweet flavor” and “pepper flavor”. SPME-GC-MS analysis revealed high concentrations of terpenes and thioethers in the headspace of the soups. A “salting-out” effect was observed in the regular salt soup with significantly higher concentrations of limonene, p-cymene, ??-caryophyllene and isopropyl disulfide identified, however, exceptions were observed in the form of dimethyl sulfide and ??-patchoulene, both of which were more abundant in the low salt soup. Partial least squares regression (PLSR) identified significant positive relationships between the volatile compounds propanol-1, hexanal, limonene, p-cymeme, isopropyl disulfide and ??-caryophyllene and the sensory attributes “salt flavor”, “yellow color”, “carrot aroma”, “overall flavor”, “overall flavor complexity” and “aftertaste”, all of which were found to be related to the regular salt soup.     

Effects of carbohydrate and noncarbohydrate sweeteners on the orange spirit volatile compounds

Various carbohydrates are permitted to sweeten spirits, whereas noncarbohydrates sweeteners are not currently approved for use. The effect of the addition of sucrose, glucose, fructose, honey, maple syrup, acesulfame K, aspartame and sorbitol on the flavor compounds of orange spirit has been studied by HS-SPME-GC analysis. Nine volatile compounds resulted affected by the sweetening: 2 aldehydes (acetaldehyde, benzaldehyde), 3 esters (ethyl-octanoate, ethyl-nonanoate and n-octyl-acetate), 2 alcohols (nonanol and linalool) and 2 hydrocarbons (δ-3-carene and valencene). Fructose, honey, acesulfame K and sorbitol had no effect on volatiles relative to an unsweetened control unlike sucrose, glucose, maple syrup and aspartame that decreased significantly (P?0.05) the headspace concentration of some volatiles. These results could be of assistance for an understanding of the role of sweeteners in the determining the extent of the volatile partition in the vapor phase affecting the flavor perception of the orange spirit.     

Chemical profiling of volatile compounds of various home‐made fruit spirits using headspace solid‐phase microextraction

Fruit spirits are typical alcoholic beverages in the Moravian region of the Czech Republic. The aim of this work was to find differences in chemical composition among volatile profiles of spirits produced from various kinds of fruits. Twenty‐four samples of seven kinds of fruit spirits (plum, apple, pear, cherry, mirabelle, apricot and raspberry spirits) were analysed for examination of their volatile profiles. The most abundant family of compounds was esters, particularly ethyl esters. Sesquiterpenes proved to be a significant group of volatile substances by observing the differences between pome and stone fruit spirits [by relative higher content of (E ,E )‐α‐farnesene and by presence of α‐zingiberene and (E )‐α‐bisabolene in volatile profiles of pome fruit spirits]. Only in stone fruit spirits were propyl decanoate and ethyl salicylate found. Some other compounds were observed as being characteristic for individual kinds of analysed fruit spirits, e.g. γ‐decalactone for apricot spirits, (E )‐β‐farnesene for apple spirits, (Z )‐9‐tetradecen‐1‐ol for mirabelle spirits or some apocarotenoids for raspberry spirits. This work could potentially be the basis for checking the fruit origin of these distillates, or a partial manual as to how to differentiate individual kinds of pome‐fruit spirits (pear and apple spirits) or stone‐fruit spirits (plum, mirabelle, apricot spirits). Copyright © 2017 The Institute of Brewing & Distilling     

Characterization of traditional Istrian dry-cured ham by means of physical and chemical analyses and volatile compounds

The aroma-active compounds of Istrian dry-cured ham were investigated by using headspace-solid phase microextraction and gas chromatography-mass spectrometry (GC-MS). Samples of biceps femoris were also evaluated by measuring physical and chemical characteristics: moisture, protein, fat, ash and NaCl content, a(w) value; colour: L*, a*, b* and oxidation of fat: TBARS test. About 50 volatile compounds were identified and quantified which belonged to several classes of chemical: 5 alcohols, 8 aldehydes, 7 alkanes, 1 ketone, 2 esters, 9 monoterpenes and 15 sesquiterpenes. Except volatile compounds derived from lipolysis and proteolysis the most abundant constituents were terpenes (62.97; 41.43%) that originate from spices added in the salting phase of the production process.     

Integrated science-based approach to study quality changes of shelf-stable food products during storage: A proof of concept on orange and mango juices

BackgroundDefining the exact shelf-life of a shelf-stable food product is still a real challenge for food manufacturers as there are many variables to be considered. Currently, many shelf-life determinations of commercial shelf-stable products are based on trial-and-error methods which could pose risks resulting in brand damage (overestimation) or food waste (underestimation). Because degradation reactions determining shelf-life are really complex, predicting quality changes remains a challenge; consequently, a scientific approach which considers multiple variables is greatly needed. Recent advances in analytical methods (e.g. GC-MS fingerprinting) and data analysis techniques (e.g. multivariate data analysis and kinetic modelling) can play a key role in this context if they are used in (accelerated) shelf-life studies. Moreover, the role of sensory evaluations should not be forgotten as changes in sensorial properties or decreases in consumer acceptance levels as a function of storage time are in most cases the primary reasons for defining the end of shelf-life.Scope and approachThis review paper focuses on research progresses in this field and addresses future challenges for quality investigation during storage and prediction of shelf-life dates. As proof of concept, the paper focuses on investigating quality changes of pasteurised shelf-stable orange and mango juices during storage.Key findings and conclusionsIn the study of shelf-stable orange and mango juices, the (combined) analytical targeted and untargeted fingerprinting approach proved to be a useful approach for identifying major-quality related chemical changes and was able to select shelf-life markers (i.e. quality parameters with a clearly observable time- (and temperature-) dependent change). In studying the kinetics of change of the monitored quality attributes, it is tempting to think that the fastest reactions will determine the shelf-life of a shelf-stable product. However, consumer acceptance through sensory evaluation plays also an important role in determining the acceptability limit and therefore the best before date. The integrated science-based approach put forward can be used to investigate quality changes of a wide range of shelf-stable products during storage.     

Headspace fingerprinting as an untargeted approach to compare novel and traditional processing technologies: A case-study on orange juice pasteurisation

As a rule, previous studies have generally addressed the comparison of novel and traditional processing technologies by a targeted approach, in the sense that only the impact on specific quality attributes is investigated. By contrast, this work focused on an untargeted strategy, in order to take into account unexpected and unintended effects of (novel) processing, and to possibly uncover unknown compounds resulting from alternative processing. The potential of headspace GC–MS fingerprinting was explored as a tool to compare the impact of thermal, high pressure (HP) and pulsed electric field (PEF) processing for mild pasteurisation of orange juice. This study demonstrated that when processing conditions are selected based on equivalent microbial safety, the impact of heat, HP and PEF pasteurisation on the volatile profile of orange juice can be considered comparable. During refrigerated storage, however, indirect impact differences were revealed, which were attributed to differences in degree of enzyme inactivation.     

Sensory characteristics of spoilage and volatile compounds associated with bacteria isolated from cooked and peeled tropical shrimps using SPME-GC-MS analysis

The spoilage potential of six bacterial species isolated from cooked and peeled tropical shrimps (Brochothrix thermosphacta, Serratia liquefaciens-like, Carnobacterium maltaromaticum, Carnobacterium divergens, Carnobacterium alterfunditum-like and Vagococcus penaei sp. nov.) was evaluated. The bacteria were inoculated into shrimps, packaged in a modified atmosphere and stored for 27 days at 8 °C. Twice a week, microbial growth, as well as chemical and sensory changes, were monitored during the storage period. The bacteria mainly involved in shrimp spoilage were B. thermosphacta, S. liquefaciens-like and C. maltaromaticum whose main characteristic odours were cheese-sour, cabbage-amine and cheese-sour-butter, respectively. The volatile fraction of the inoculated shrimp samples was analysed by solid-phase microextraction (SPME) and gas chromatography coupled to mass spectrometry (GC-MS). This method showed that the characteristic odours were most likely induced by the production of volatile compounds such as 3-methyl-1-butanal, 2,3-butanedione, 2-methyl-1-butanal, 2,3-heptanedione and trimethylamine.     

Enhancement of volatile aromatic compounds in black raspberry wines via enzymatic treatment

Robus coreanus Miquel is widely used in the production of Korean black raspberry (KBR) wine owing to its health benefits and commercial value. The effects of three different commercially available glycosidase enzymes on the volatile compounds in KBR wines were investigated with large‐scale fermentation to develop a high‐flavour‐quality wine. Volatile aroma compounds from the wines were analysed using headspace‐solid phase micro‐extraction‐gas chromatography–mass spectrometry (HS‐SPME‐GC–MS) and sensory evaluations were performed to evaluate the flavour characteristics. KBR wines treated with commercial enzymes yielded high concentrations of terpenes and esters compared with the control wine because the odourless non‐volatile glycosides in KBR wines were converted to their corresponding free forms by the enzymes. HS‐SPME‐GC–MS‐SIM analysis showed that the primary monoterpene compounds in KBR wines treated by the enzymes were myrtenol, linalool, citronellol and a significant quantity of compounds such as 2‐phenyl ethanol and ethyl benzoate, which contributed to the flavour of KBR wine, as determined by GC‐FID. KBR wines treated with the enzymes exhibited different sensory characteristics from the control wine owing to higher intensity of floral and fruity aromas. KBR wine treated with CYTOLASE PCL5 on a large scale exhibited the highest sensory preference. Copyright © 2017 The Institute of Brewing & Distilling     

Rice vinegars of different origins: discriminative characteristics based on solid‐phase microextraction and gas chromatography with mass spectrometry,an electronic nose,electronic tongue and sensory evaluation

Eight kinds of commercial rice vinegars from Korea, China and Japan were selected to evaluate their flavour‐related discriminative characteristics based on solid‐phase microextraction and gas chromatography with mass spectrometry (SPME/GC–MS), an electronic nose (e‐nose), electronic tongue (e‐tongue) and subjective sensory evaluation. Principal component analysis patterns based on SPME/GC–MS provided a clear categorical discrimination among the vinegars of three origins. The distribution patterns of the samples were similar between SPME/GC–MS and e‐nose analyses and Korean vinegars were clearly discriminated. A high correlation coefficient was determined between SPME/GC–MS and e‐nose on acetaldehyde (0.948) and diacetyl (0.970). e‐Tongue‐based principal component analysis patterns were subdivided into three regions according to the origin, and Chinese vinegars were clearly discriminated. Sensory panelists recorded origin‐specific scores on flavours for all the samples. In conclusion, SPME/GC–MS, e‐nose and e‐tongue analyses may be useful for discrimination of flavour profiles of rice vinegars of different producer origin. Copyright © 2017 The Institute of Brewing & Distilling     

Production of volatile compounds by hairy root cultures of Cichorium intybus L under the influence of fungal elicitors and their analysis using solid‐phase micro extraction gas chromatography–mass spectrometry

Hairy root cultures of Cichorium intybus L produced volatile aromatic compounds under the influence of fungal elicitors. It was observed that the intensity of the production of volatile aromatic compounds in the hairy root cultures of C intybus with 10 ml l^?1 media filtrate (MF) of Phytopthora parasitica var nicotiana reached a maximum on the 21st day, as seen by a quantitative flavour profiling method. It was noted that, during the time course, treatment with 10 ml l^?1 MF of P parasitica to the MS basal liquid medium containing hairy root cultures of chicory resulted in changed root morphology with cell wall thickening and shear. The components of the volatile aromatic compounds were identified as a propyl isovalerate, undecanal, nonanol, isoamyl nonanoate and 2‐decene‐1‐ol. The mass spectra of all these compounds matched well with the NIST/EPA/NIH library and by comparing with the Kovats index of volatile compounds. The major fruity note was due to the presence of two of the major volatile components, namely propyl isovalerate and isoamyl nonanoate, which were also produced at higher concentration on day 21. This response of chicory hairy root cultures to the fungal elicitor producing volatile aromatic compounds would imply eco‐physiological functions, possibly for plant defence system. Copyright © 2003 Society of Chemical Industry     

Effects of supercritical CO2 and N2O pasteurisation on the quality of fresh apple juice

Supercritical pasteurisation is receiving increasing attention as an alternative technology for foodstuff pasteurisation, but often the possible effects on the perceptible quality are not sufficiently considered.     

Estimation of the honeydew ratio in honey samples from their physicochemical data and from their volatile composition obtained by SPME and GC‐MS

Differentiation of nectar and honeydew honeys is difficult, not only because of the wide variability in composition and organoleptic properties among samples from the same source, but also because of the frequent existence of honeys resulting from a blend of nectar and honeydew. A mathematical expression to evaluate the relative presence of honeydew in a honey sample (HD) has been developed from relevant physicochemical properties of honey samples selected as highly representative of both honey types on the basis of their physico‐chemical and melissopalynological analysis. As honey aroma depends on its volatiles composition, GC‐MS analysis of the volatile fraction obtained by SPME has been carried out in order to evaluate its usefulness in honey source differentiation. Stepwise regression from multicomponent volatiles data was used for the estimation of HD and for determining which volatile compounds were related to the different honey sources. Copyright © 2004 Society of Chemical Industry