The effectiveness of multi‐element fingerprints for identifying the geographical origin of wheat

Totally 270 wheat samples with ten genotypes of 2010/2011, 2011/2012 and 2012/2013 from three regions were collected, and the multi‐elemental compositions (Mg, Al, Ca, Mn, Fe, Cu, Zn, As, Sr, Mo, Cd, Ba, Pb) were analysed with high‐resolution inductively coupled plasma mass spectrometry (HR‐ICP‐MS). Multiway analysis of variance was employed to investigate the influences of region, genotype, harvest year and their interactions on all elements. The contribution rates of variances were computed, and the results showed that the elements of Mn, Sr, Mo and Cd were closely related to region explaining 34.2%, 39.6%, 35.0% and 78.8% of the total variation, respectively. The genotype contributed most for the variation of Ba, accounting for 27.3%, and the other elements were affected by the harvest year. Mn, Sr, Mo and Cd can be used for establishing the robust discriminant model with the correct classification rate of 98.5% to identify the geographical origin of wheat.     

Easy classification of traditional Minas cheeses using artificial neural networks and discriminant analysis

The classification of traditional Minas cheese (TMC) from different regions is important to ensure authenticity. Different chemometric approaches were used to discriminate TMCs from three different regions (Serro, Canastra and Araxá) of Minas Gerais, Brazil. The data obtained from the literature were used to develop an artificial neural network and to obtain linear discriminant functions, which were able to classify 100% of cheeses from different regions as a function of physico‐chemical composition. Both chemometric methods can be very useful tools to discriminate TMC from different regions based on physico‐chemical data which are obtained in a very quick and simple way.     

Application of multi‐element viscoelastic models to freshness evaluation of beef based on the viscoelasticity principle

The aims of this work were to develop multi‐element viscoelastic models for beef and apply them to detect total volatile basic nitrogen (TVB‐N) content for freshness evaluation. The deformation data were collected by a viscoelasticity detection system that employed the airflow and laser technique. Then, TVB‐N contents were measured to determine the freshness of samples during storage. A universal global optimization (UGO) algorithm was applied to fit the deformation data. Various multi‐element viscoelastic models including the Burgers, six‐element and eight‐element models were built using the obtained fitting parameters, and different viscoelastic parameters representing the degree of beef spoilage were obtained. All the viscoelastic parameters of each multi‐element model and parameter combinations of the selected six‐element model were employed to build mathematical models for predicting TVB‐N content by support vector machine regression (SVR). In comparison, the six‐element model with all the viscoelastic parameters performed the best and was determined to predict TVB‐N content with correlation coefficient in the prediction set (R_P) of 0.891 and root mean squared error in the prediction set (RMSEP) of 1.467 mg/100 g. Based on the results of parameter combinations, combination (E₂, E₃, E₁, η₁, η₂) from the six‐element model performed the best, which was comparatively inferior to all the viscoelastic parameters of the six‐element model. Results demonstrated that it was possible to predict TVB‐N content for freshness evaluation by applying method of developing multi‐element model based on the viscoelasticity with chemometrics.     

The effects of starter cultures on chemical,biochemical and sensory properties of low‐fat Tulum cheeses during ripening

Three different commercial starter cultures, Choozit^? MA 11 (MA ), Choozit^? BT 01 (BT ) and Choozit^? Feta A (Feta), were used to remedy textural and aromatic defects and improve the overall quality of low‐fat Tulum cheeses. Chemical and sensory analyses as well as electrophoresis were performed. Supplemental yoghurt bacteria and Lactobacillus helveticus were found to be key contributors in proteolysis with varying protein breakdown capacities. The results suggest that using appropriate culture combinations could result in low‐fat Tulum cheeses with better sensory characteristics and proteolysis rates.     

The compositional properties,proteolytic–lipolytic maturation parameters and volatile compositions of commercial enzyme‐modified cheeses with different cheese flavours

Eight different commercial enzyme‐modified cheeses (EMCs) were analysed, and the distinctive/common features of the products and production methods were investigated. Results showed that the total free fatty acid contents of EMC samples were 10 to 100 times higher than the values reported for the related cheese varieties. A total of 37 volatile compounds were identified, and acids were found as the most dominant group in all EMC samples. While furan compounds and 2‐acetylpyrrole were most intensively detected in the goat cheese EMC, methyl ketones were found in the highest amounts in Blue cheese EMC.     

Determination of the geographical origin of wine using joint analysis of elemental and isotopic composition. II—Differentiation of the principal production zones in france for the 1990 vintage

Stable isotope analysis of grape juices and fermented products involving 2H-NMR spectroscopy and isotope ratio mass spectroscopy was carried out in combination with elemental determinations performed by atomic absorption spectroscopy using flame and thermal ionisation. One hundred and sixty five grape samples were carefully collected in well-defined vineyards of France situated in Alsace, Burgundy, Beaujolais and the Loire Valley. Moreover, the samples from Burgundy were picked from four typical Appellations (Cǒtes de Nuits, Cǒtes de Beaune, Cǒtes Chalonnaises and Mǎconnais) in order to ‘zoom’ the approach to smaller production areas. An exhaustive statistical evaluation of the 165 ± 16 data set was carried out by analysis of variance and principal component analysis. To conclude this study, the classification of the samples in typical Appellations was carried out by discriminant analysis with a nearly 100% degree of achievement.     

Influence of manufacturing conditions on thermo‐physical properties of ripened experimental Emmental‐type cheese and comparison with commercial Emmental cheese

Experimental Emmental cheese was produced at pilot plant scale with varied process conditions, and the ripened cheeses were analysed in terms of thermo‐physical properties. The amount of propionic acid and the temperature at tan δ_max ( loss factor) were significantly influenced by varied process parameters. Experimental cheeses were compared to commercial Emmental cheese by the application of principal component analysis. Commercial Emmental cheese was clearly discriminated from experimental Emmental cheese mainly due to the melting behaviour. The results allow the establishment of a small‐scale process for Emmental cheese production to promote product development on a time and cost‐saving level.     

The comparison of biosorption of nutritionally significant minerals in single‐ and multi‐mineral systems by the edible microalga Spirulina sp.

BACKGROUND: This paper deals with the biosorption process as a method of enrichment of natural biomass of the edible microalga Spirulina sp. with microelement metal ions, which is of significance in terms of animal nutrition. The influence of the following process parameters was studied for the biosorption of Cr(III): pH and biomass concentration on kinetics and equilibrium of biosorption. The enrichment process were performed in single‐ and multi‐mineral systems for nutritionally significant minerals such as Cu(II), Mn(II), Co(II), Zn(II) and Cr(III) under the conditions that were determined for Cr(III). RESULTS: The best operational parameters for the process were selected as pH 5 and Cs 1 g L^?1. The maximum biosorption capacity 71.2 mg g^?1, 18.4 mg g^?1, 83.9 mg g^?1, 31. 8 mg g^?1 and 26.5 mg g^?1, were reached for Cu(II), Mn(II), Co(II), Zn(II) and Cr(III), respectively. To cover 100% of animal demand on microelements, 4.91 g of the preparation for laying hens and 9 g for swine of enriched microalgae in the single‐metal system should be added to 1 kg of fodder. In the multi‐metal system the competition between microelements was high enough to make it impossible to reach a suitable ratio between bound metal ions. CONCLUSIONS: Two methods of production of mineral feed additives were proposed: a single‐metal system and a multi‐metal system. Performing the biosorption process in the single‐metal system enabled the preparation of additives with the desired composition. Carrying out biosorption in the multi‐metal system is easier, technologically, but the ratio of bound microelements is difficult to predict. Copyright © 2009 Society of Chemical Industry     

Multi‐element characterisation of carob,fig and almond liqueurs by MP‐AES

Carob pod, fig and almond liqueurs are produced in various Mediterranean regions. This work reports the mineral content of these traditional beverages and evaluates the influence of the raw material. Twenty‐five fruit liqueurs from 16 producers were analysed. A simple open‐vessel sample mineralization by wet digestion using nitric acid–hydrogen peroxide (1:1) was used before spectrometric analysis. Nine essential elements (Cu, Ca, Mg, Na, K, Fe, Zn, Mn and P) and two non‐essentials (Cd and Pb) were quantified by microwave plasma–atomic emission spectrometry (MP‐AES). Carob liqueur presented the broader profile of minerals and was the only fruit liqueur containing iron (72.7% of samples), phosphorous, manganese and low levels of lead (in two of the 11 samples). Conversely, almond liqueurs contained the lowest mineral content with only five elements detected. Fruit liqueurs showed variability in mineral content even within the same liqueur, presumably as a consequence of the different manufacturing processes. Despite this variability, application of principal component analysis to essential mineral concentrations (K, Na, Ca, Mg, Mn, Fe and Zn) resulted in satisfactory classification (PC1 and PC2 accounting for 78.5% of the total variance) of the Portuguese liqueurs evaluated. Copyright © 2018 The Institute of Brewing & Distilling     

The effect of using an exopolysaccharide‐producing culture on the physicochemical properties of low‐fat and reduced‐fat Kasar cheeses

A mixed starter culture containing exopolysaccharide (EPS)‐producing strains of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus was combined with Lactobacillus helveticus LH301 and used in the manufacture of low‐fat and reduced‐fat Kasar cheeses. For comparison, low‐fat (C10) and reduced‐fat (C20) cheeses were made using EPS‐producing (EPS⁺) starter strain and EPS‐non‐producing (EPS^?) starter strain. The physicochemical properties of the cheeses were assessed in terms of chemical composition, texture, microstructure and microbial content over 90 days. Cheeses made with EPS‐producing culture (EPS10 and EPS20) had lower protein contents than control cheeses with 10% and 20% fat in dry basis (C10 and C20). Scanning electron microscopy images showed that using EPS‐producing culture resulted in a less compact protein matrix and sponge‐like structure in the cheese samples. In general, cheeses made using EPS‐producing culture had lower total viable counts. This could be related to the reduced survivability of EPS‐producing cells in the cheese matrix during ripening due to autolysis ability.     

Chemical composition and sensory analysis of cheese whey‐based beverages using kefir grains as starter culture

The aim of the present work was to evaluate the use of the kefir grains as a starter culture for tradicional milk kefir beverage and for cheese whey‐based beverages production. Fermentation was performed by inoculating kefir grains in milk (ML), cheese whey (CW) and deproteinised cheese whey (DCW). Erlenmeyers containing kefir grains and different substrates were statically incubated for 72 h at 25 °C. Lactose, ethanol, lactic acid, acetic acid, acetaldehyde, ethyl acetate, isoamyl alcohol, isobutanol, 1‐propanol, isopentyl alcohol and 1‐hexanol were identified and quantified by high‐performance liquid chromatography and GC‐FID. The results showed that kefir grains were able to utilise lactose in 60 h from ML and 72 h from CW and DCW and produce similar amounts of ethanol (～12 g L^?1), lactic acid (～6 g L^?1) and acetic acid (～1.5 g L^?1) to those obtained during milk fermentation. Based on the chemical characteristics and acceptance in the sensory analysis, the kefir grains showed potential to be used for developing cheese whey‐based beverages.     

Rapid evaluation and discrimination of γ‐irradiated carbohydrates using FT‐Raman spectroscopy and canonical discriminant analysis

Chemical changes induced by gamma irradiation of selected sugar systems—honey and fructose—were investigated through their molecular fingerprint using Fourier transform Raman spectroscopy (FT‐Raman). Generalized two‐dimensional (2‐D) correlation spectroscopy was applied to FT‐Raman spectra of the control and 17 kGy irradiated fructose to elucidate changes in the chemical structure upon irradiation. The irradiation induced changes in the ring (below 700 cm^?1) and conformational structure (800–1500 cm^?1) of fructose were identified by means of a 2‐D FT‐Raman correlation spectroscopy. The irradiation damage depicted from the C? H stretch region (2800–3000 cm^?1) of the FT‐Raman spectra of honey was used to develop a pattern recognition model for classifying honey based on the irradiation dose. A hybrid partial least squares (PLS)–canonical variate analysis (CVA) with the optimum number of factors from PLS was used for rapid discrimination of honeys irradiated at 1, 5, 10 or 17 kGy. The present study demonstrated that FT‐Raman spectroscopy, together with chemometrics, could be a rapid tool for classification of foodstuffs with high sugar content and provides a viable option to explore radiation‐induced modifications to sugar systems subjected to irradiation processing. Copyright © 2007 Society of Chemical Industry     

Use of Multi‐Intake Temporal Dominance of Sensations (TDS) to Evaluate the Influence of Cheese on Wine Perception

Though the gastronomic sector recommends certain wine–cheese associations, there is little sensory evidence on how cheese influences the perception of wine. It was the aim of this study to dynamically characterize 4 wines as they would be perceived when consumed with and without cheese. The tasting protocol was based on multi‐intake temporal dominance of sensations (TDS) coupled with hedonic rating. In the 1st session, 31 French wine and cheese consumers evaluated the wines (Pacherenc, Sancerre, Bourgogne, and Madiran) over 3 consecutive sips. In the following sessions, they performed the same task, but eating small portions of cheese (Epoisses, Comté, Roquefort, Crottin de Chavignol) between sips. All cheeses were tasted with all wines over 4 sessions. TDS data were mainly analyzed in terms of each attribute's duration of dominance by analysis of variance, multivariate analysis of variance, and canonical variate analysis. Results showed that cheese consumption had an impact (P < 0.1) on dominance duration of attributes and on preference for most wines. For example, in Madiran, all cheeses reduced dominance duration (P < 0.01) of astringency and sourness and increased duration of red fruit aroma. Although the number of consumers was small to make extended general conclusions on wine's preference, significant changes were observed before and after cheese intake.