Methodologies for the Characterization of the Quality of Dairy Products

International audienceThe growing interest of consumers in food quality and safety issues has contributed to the increasing demand for sensitive and rapid analytical technologies. Physicochemical, textural, sensory, etc., methods have been used to evaluate the quality and authenticity of milk and dairy products. Despite the importance of these standard methods, they are expensive and time consuming. Recently, spectroscopic methods have shown great potential due to speed of analysis, minimal sample preparation, high repeatability, low cost, and, most of all, the fact that these techniques are noninvasive and nondestructive and, therefore, could be applied to any on-line monitoring system.This chapter gave examples of the application of the most commonly traditional methods for the determination of the quality of milk and dairy products. A special focus is devoted to the use of infrared and fluorescence spectroscopies for the evaluation of the quality of dairy products

Application of Fourier-transform mid infrared spectroscopy for the monitoring of pound cakes quality during storage

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Evaluation and monitoring of the quality of sausages by different analytical techniques over the last five years

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Efficiency of Rosemary and Basil Essential Oils on the Shelf-Life Extension of Atlantic Mackerel (Scomber scombrus) Fillets Stored at 2°C

International audienceAbstract The objective of the present study was to evaluate the impact of rosemary and basil essential oils (EOs) onthe quality of Atlantic mackerel fillets stored at 2°C up to 15 days. Atlantic mackerel (Scomber scombrus) fillets were periodically evaluated to assess their textural, color, physicochemical, andspectral characteristics. The results indicated that rosemary and basil treatments were effective for inhibiting the formation of total volatile basic nitrogen (TVB-N) and lipid oxidation products during storage. Based on TVB-N values, the shelf life of Atlantic mackerel fillets treated with rosemary and basil EOs was extended by 2 and 5 days, respectively, compared to the control group. Similar results were obtained with thiobarbituricacid–reactive substance analysis, which demonstrated an extended shelf life of Atlantic mackerel immersed with rosemary and basil EOs of 2 and 3 days, respectively, compared to the control group. The factorial discriminant analysis applied on the concatenated first five principal components corresponding to the physicochemical, textural, color, and fluorescence measurements allowed clear discrimination of the three groups, because a correct classification rate of 93.3% was obtained. Therefore, treatment with basil and rosemary EOs, as natural biopreservative compounds, could present a high-potential application in the seafood industry

Texture staling of pound cakes assessed by front face fluorescence spectroscopy in tandem with chemometric analysis

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Développement d'un spectrofluorimètre portatif pour mesurer la qualité des fromages

The determination of some chemical parameters of Saint-Nectaire cheese samples (fat, dry matter (DM), pH, total protein (TP) and soluble protein (SP)) was investigated using fluorescence spectroscopy. A total of 12 cheeses (with a ripening time of 1 month) produced using different manufacturing processes and ripened in different conditions – farmhouse Saint-Nectaire ripened at a farmhouse ($n=3)$, farmhouse Saint-Nectaire ripened at a dairy plant ($n=3)$, Saint-Nectaire “Laitier” ripened at a dairy plant ($n=3)$ and Savaron ($n=3)$ ripened at a dairy plant – were analyzed by laboratory and portable spectrofluorometers developed at the Foodstuffs Unit of ENITA Clermont-Ferrand. Partial least squares (PLS) regression with the leave-one-out cross-validation technique was used to perform calibration models. The best results for DM (R$^{2 }$ = 0.91; ratio of standard deviation to root mean square error of prediction (RPD) = 3.37), TP (R$^{2 }$ = 0.86; RPD = 2.71), fat (R$^{2 }$ = 0.83; RPD = 2.42) and SP (R$^{2 }$ = 0.65; RPD = 1.66) were obtained with the portable fluorometer, with the excitation wavelength set at 380 nm. Regarding the prediction of pH value, the best results were also obtained with the portable fluorometer with excitation set at 280 nm (R$^{2 }$ = 0.74; RPD = 1.98). It could be concluded that the portable spectrofluorometer could be used as a suitable technique for the prediction of DM, TP and fat. The SP and pH could also be estimated, but with much lower precision.La mesure de quelques paramètres chimiques de fromages de Saint-Nectaire (matière grasse, extrait sec, pH, protéines totales et protéines solubles) a été déterminée par spectroscopie de fluorescence. Au total, 12 fromages de Saint-Nectaire (ayant un temps d'affinage de 1 mois) ont été fabriqués en utilisant différents procédés de fabrication et conditions d'affinage – Saint-Nectaire fermier affiné dans une ferme ($n=3)$, Saint-Nectaire fermier affiné dans une laiterie ($n=3)$, Saint-Nectaire “Laitier” affiné dans une laiterie ($n=3)$ et Savaron ($n=3)$ affiné dans une laiterie – ont été analysés par un spectrofluorimètre du laboratoire et le spectrofluorimètre portatif développé au sein de l'Unité de Recherche "Typicité des Produits Alimentaires" (UR TPA) de l'ENITA de Clermont-Ferrand. La méthode des moindres carrés partiels avec validation croisée a été utilisée pour développer des modèles de calibrage, et ce pour tous les paramètres chimiques. Les meilleurs résultats pour l'extrait sec (R$^{2}$ = 0,91 ; RPD = 3,37), les protéines totales (R$^{2}$ = 0,86 ; RPD = 2,71), la matière grasse (R$^{2}$ = 0,83 ; RPD = 2,42) et les protéines solubles (R$^{2}$ = 0,65 ; RPD = 1,66) ont été obtenus avec le spectrofluorimètre portatif, après excitation à 380 nm. Concernant la détermination de la valeur du pH, les meilleurs résultats ont été obtenus également avec le spectrofluorimètre portatif après excitation à 280 nm (R$^{2}$ = 0,74 ; RPD = 1,98). Le spectrofluorimètre portatif peut être considéré comme une technique appropriée pour la détermination de l'extrait sec et des teneurs en protéines totales et en matière grasse. Les teneurs en protéines solubles et le pH peuvent être également prédits, mais avec une précision beaucoup plus faible

Quality Evaluation of Fish and Other Seafood by Traditional and Nondestructive Instrumental Methods: Advantages and Limitations

International audienceAlthough being one of the most vulnerable and perishable products, fish and other seafoods provide a wide range of health-promoting compounds. Recently, the growing interest of consumers in food quality and safety issues has contributed to the increasing demand for sensitive and rapid analytical technologies. Several traditional physicochemical, textural, sensory, and electrical methods have been used to evaluate freshness and authentication of fish and other seafood products. Despite the importance of these standard methods, they are expensive and time-consuming, and often susceptible to large sources of variation. Recently, spectroscopic methods and other emerging techniques have shown great potential due to speed of analysis, minimal sample preparation, high repeatability, low cost, and, most of all, the fact that these techniques are noninvasive and nondestructive and, therefore, could be applied to any online monitoring system. This review describes firstly and briefly the basic principles of multivariate data analysis, followed by the most commonly traditional methods used for the determination of the freshness and authenticity of fish and other seafood products. A special focus is put on the use of rapid and nondestructive techniques (spectroscopic techniques and instrumental sensors) to address several issues related to the quality of these products. Moreover, the advantages and limitations of each technique are reviewed and some perspectives are also given

Monitoring of mild heat treatment of camel milk by front-face fluorescence spectroscopy

International audienceThe potentiality of the front-face fluorescence spectroscopy coupled with chemometric tools to characterize changes in camel milk following thermal treatments in the 55–75 °C temperature range from 0.5 min up to 30 min was studied. Nicotinamide adenine dinucleotide (NADH), fluorescent Maillard reaction products (FMRP) and vitamin A fluorescence spectra were collected on camel milk samples. Using principal component analysis (PCA), the vitamin A spectra allowed some discrimination between milk samples according to heat treatment intensity and holding time. The best results was obtained by applying common components and specific weights analysis (CCSWA) to the three spectral data sets, since a clear differentiation between camel milk samples preheated at 70 and 75 °C from the others was achieved. Apparent activation energy of camel milk determined from NADH, FMRP and vitamin A spectra was of 85.1, 84.2 and 47.3 kJ mol−1, respectively. The spectral patterns of the CCSWA model enabled us to get information about the molecular changes occurring in camel milk fluorophores during heat treatment

Analytical methods coupled with chemometric tools for determining the authenticity and detecting the adulteration of dairy products: A review

International audienceAuthenticity of dairy products has become an urgent issue for producers, researchers, governments, consumers and so on due to the increase of falsification procedures inducing lost large of money as well as the confidence of consumers. The determination of the authenticity and the detection of adulteration of milk and dairy products have been determined by several analytical techniques (e.g., physico-chemical, sensory, chromatography, and so on). Although these methods are considered as the reference ones, they required sophisticated analytical equipment's and skilled operators; they are also time consuming and need both the purchase and disposal of chemical reagents. Therefore, there is a need to find cheap and fast methods for the determination of the authenticity and the detection of adulteration of these products. Thus, spectroscopic techniques such as fluorescence spectroscopy, near infrared (NIR), mid infrared (MIR), nuclear magnetic resonance (NMR), among others, in combination with multivariate data analysis methods could be considered helpful tools in this domain. The advantages and disadvantages of each technique will be also discussed in this review