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

Sausages are among the most vulnerable and perishable products, although those products are an important source of essential nutrients for human organisms. The evaluation of the quality of sausages becomes more and more required by consumers, producers, and authorities to thwarter falsification. Numerous analytical techniques including chemical, sensory, chromatography, and so on, are employed for the determination of the quality and authenticity of sausages. These methods are expensive and time consuming, and are often sensitive to significant sources of variation. Therefore, rapid analytical techniques such as fluorescence spectroscopy, near infrared (NIR), mid infrared (MIR), nuclear magnetic resonance (NMR), among others were considered helpful tools in this domain. This review will identify current gaps related to different analytical techniques in assessing and monitoring the quality of sausages and discuss the drawbacks of existing analytical methods regarding the quality and authenticity of sausages from 2015 up to now.

A review combining emerging techniques with classical ones for the determination of biscuit quality: advantages and drawbacks.

The production of biscuit and biscuit-like products has faced many challenges due to changes in consumer behavior and eating habits. Today's consumer is looking for safe products not only with fresh-like and pleasant taste, but also with long shelf life and health benefits. Therefore, the potentiality of the use of healthier fat and the incorporation of natural antioxidant in the formulation of biscuit has interested, recently, the attention of researchers. The determination of the biscuit quality could be performed by several techniques (e.g., physical, chemical, sensory, calorimetry and chromatography). These classical analyses are unfortunately destructive, expensive, polluting and above all very heavy, to implement when many samples must be prepared to be analyzed. Therefore, there is a need to find fast analytical techniques for the determination of the quality of cereal products like biscuits. Emerging techniques such as near infrared (NIR), mid infrared (MIR) and front face fluorescence spectroscopy (FFFS), coupled with chemometric tools have many potential advantages and are introduced, recently, as promising techniques for the assessment of the biscuit quality.

Application of new emerging techniques in combination with classical methods for the determination of the quality and authenticity of olive oil: a review.

The determination of the quality and authenticity of olive oil becomes more and more required by producers, consumers, and authorities to thwarter falsification. Several analytical techniques including chemical, sensory, chromatography, and so on, are used for the determination of the quality and authenticity of olive oil. Although these methods are considered as the reference ones, they are cumbersome, time-consuming and destructive. Therefore, rapid analytical techniques such as fluorescence, ultraviolet-visible, near infrared, and mid infrared spectroscopies, electronic sensing, among others, are more and more used for the determination of the quality and authenticity of olive oils. This review will identify current gaps related to different analytical techniques in olive oil authentication and discuss the drawbacks of existing analytical methods concerning olive oil authenticity from 2010 up to now.

Use of mid-infrared spectroscopy for quality monitoring and the prediction of physicochemical parameters of dry fermented chicken sausages enriched with sesame flour.

BACKGROUND: This study aimed to investigate the effects of the supplementation of sesame flour in fermented chicken sausages ('S1' containing 800 g kg-1 chicken fillet, 180 g kg-1 veal fat and 20 g kg-1 sesame flour and 'S2' containing 800 g kg-1 chicken fillet, 160 g kg-1 veal fat and 40 g kg-1 sesame flour) compared with control sausages (containing 800 g kg-1 chicken fillet and 200 g kg-1 veal fat) on the physico-chemical characteristics, texture, and structure during the fermentation stage. RESULTS: The physicochemical parameters of samples belonging to the control, S1, and S2 batches were significantly affected by the addition of sesame flour and the fermentation stage. For instance: (i) the lowest protein content was observed for control samples on day 1 (61.4 ± 6.52 g kg-1 ) whereas the highest level was noted for S2 samples on day 15 (327.5 ± 22.2 g kg-1 ), and (ii) an inverse trend was observed for the fat content because the lowest content was observed for samples in the S2 batch on day 1 (129.0 ± 5.30 g kg-1 ) whereas the highest fat content was noted for samples belonging to control batch on day 15 (332.0 ± 1.29 g kg-1 ). The application of statistical methods to mid-infrared spectroscopy allowed clear discrimination between control, S1, and S2 batches. The addition of sesame flour in the recipes induced some modification in the secondary structure because ß-turn levels ranged from 39.30 to 34.50, 36.76 to 34.70, and 38.93 to 34.70 for control, S1, and S2 batches, respectively, throughout the fermentation stage. Sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) showed a similar protein profile pattern in the three batches on days 1 and 5, but on day 10 control and S2 batches showed the most intense degradation of myofibrillar proteins. CONCLUSION: The results demonstrated that mid-infrared spectroscopy coupled with chemometric tools could be used as a rapid screening tool to assess and monitor the quality of dry chicken sausages enriched with sesame flour throughout the fermentation stage. © 2022 Society of Chemical Industry.

Preliminary study on the potential application of Fourier-transform mid-infrared for the evaluation of overall quality and authenticity of Moroccan virgin olive oil.

BACKGROUND: Olive oil provides a wide range of health-promoting compounds. The quality of olive oil is an even more complex concept as it is affected by several factors, such as variety, season, stage of maturation, extraction processing, and so on. The main objective of this study was to determine the potential of chemical and mid-infrared spectroscopy techniques to determine the quality and authenticity of virgin olive oil (VOO). For this, we studied 41 VOOs originating from five regions of Morocco (Fez/Meknes, Eastern, Northern, Beni-Mellal/Khenifra, and Marrakech/Safi) and produced using different agricultural and technological conditions during two successive crop seasons (2015-2016 and 2016-2017). RESULTS: By applying principal component analysis and factorial discriminant analysis with leave-one-out validation to the mid-infrared spectroscopy, clear discrimination between VOO samples according to their geographic origin and variety was observed, with correct classification rates of 91.87% and 91.87% being observed respectively. The application of partial least-squares regression to mid-infrared and chemical data sets allowed excellent prediction of free acidity, peroxide value, k270 , and chlorophyll level with R2 of 0.99, 0.97, 0.98, and 0.93 respectively, and good prediction of k232 (R2 = 0.84). CONCLUSION: The results demonstrate that mid-infrared spectroscopy coupled with chemometric tools could be used as a rapid screening tool for evaluating the overall quality and authenticity of VOO. © 2020 Society of Chemical Industry.

Effect of succinylation on the secondary structures, surface, and thermal properties of date palm pollen protein concentrate.

The present study was attempted to investigate the effect of succinylation, as chemical modification, on the functionality of male date palm pollen protein concentrate (MDPPPC). Succinylation was applied at two levels, 4 and 8 mol of succinic acid per mole of lysine. 4 M and 8 M were compared to the native MDPPPC. Findings proved that succinylation improved the surface properties of pollen protein including solubility and surfactant activity. Increased solubility of succinylated MDPPPC has been noticed especially in pH superior to pHi. The results from the differential scanning calorimetry showed a significant decrease (P < 0.05) of the denaturation temperature and the heat enthalpy for succinylated MDPPPC. ß turn of succinylated MDPPPC increased significantly (P < 0.05) at the expense of ß sheet indicating that the protein gained more mobility after succinylation which explains the enhancement of the functional properties and promotes the use of succinylated protein as a techno-functional ingredient.

Fluorescence spectroscopy coupled with independent components analysis to monitor molecular changes during heating and cooling of Cantal-type cheeses with different NaCl and KCl contents.

BACKGROUND: Reduction of NaCl content of cheeses has received considerable attention by research during the past decades because of its health effects. Nonetheless, NaCl reduction is a challenge since it plays an important role in cheese quality, such as structure, texture and functional properties. Several methods were used to evaluate the effect of NaCl on these attributes. In this study, Cantal-type cheeses with different salts (NaCl and KCl) were analyzed for their structure at a molecular level and rheological properties during heating (20-60 °C) and cooling (60-20 °C). The structure was investigated by synchronous fluorescence spectroscopy (SFS) and the rheological properties by small-amplitude oscillatory test. RESULTS: Independent components analysis (ICA) gave three independent components that were attributed to coenzyme/Maillard reaction products (IC1), tryptophan (IC2) and vitamin A (IC3). Signal proportions of each IC depicted information regarding the changes in those fluorophores with salts, heating and cooling. In addition, canonical correlation analysis (CCA) of the IC proportions and rheological measurements related modifications at a molecular level evaluated by fluorescence to cheese texture (0.34 < R2 < 0.99). CONCLUSION: This study demonstrated that SFS can monitor and characterize modification of Cantal-type cheeses at a molecular level, based on the analysis of the fluorescence spectra by ICA. The nature of correlation between signal proportions and the rheological parameters depicted that rheological attributes of cheeses observed at the macroscopic level can be derived from fluorescence spectra. © 2017 Society of Chemical Industry.

Quality evaluation of fish and other seafood by traditional and nondestructive instrumental methods: Advantages and limitations.

Although 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.

Effects of heating and calcium and phosphate mineral supplementation on the physical properties of rennet-induced coagulation of camel and cow milk gels.

The physical properties of rennet-induced coagulation of preheated camel and cow milk gels (50 and 70 °C for 10 min) enriched with calcium chloride (CaCl2) and hydrogen phosphate dihydrate (Na2HPO42H2O) were evaluated using the dynamic low amplitude oscillatory shear analysis. The storage modulus (G') and loss modulus (G") of camel milk gels showed significant (P < 0·05) lower values than those of cow milk gels. The preheating of camel milk at 50 °C affected negatively the gelation properties, while the preheating at 70 °C prevented the formation of rennet-induced milk gels. No effect was observed on the gelation properties of cow milk gels. The CaCl2 added at 10 and 20 mM to preheated camel and cow milk reduced significantly (P < 0·05) the gelation time and increased the gel firmness. In contrast, Na2HPO42H2O added at 10 and 20 mM induced the formation of weak gels for preheated camel and cow milk at 50 °C, and even no gelation for preheated camel milk at 70 °C.

Rennet-induced coagulation of raw and heated camel and cow milk gels determined by instrumental techniques: effects of added calcium and phosphate.

BACKGROUND: The potentiality of the front-face fluorescence spectroscopy and rheological measurements combined with chemometric tools to characterise the structure evolution during coagulation of raw and preheated camel and cow milk at 50 and 70 °C with/without added calcium and phosphate was evaluated. Tryptophan and vitamin A fluorescence spectra were collected during the gelation of milk at 0, 10, 20, 30, 40, and 45 min after the addition of rennet-induced coagulation. In parallel, the storage modulus (G'), loss modulus (G″) and tan delta (tan δ) were determined using low amplitude oscillation shear analysis. RESULTS: The principal component analysis (PCA) applied to the normalised tryptophan spectra allowed the gels made with camel milk to be differentiated from those of cow milk on the one hand, and to monitor protein structure modifications during the gelation, on the other hand. The common components and specific weights analysis (CCSWA) applied jointly to the fluorescence and rheological data sets permitted a clear separation of raw milk gels from those preheated at 50 and 70 °C. CONCLUSION: The front-face fluorescence spectroscopy method coupled with multi-variate statistical analyses showed a high capacity for studying changes in the micelle structure throughout the rennet-induced coagulation process. © 2017 Society of Chemical Industry.

Rheological and physical properties of camel and cow milk gels enriched with phosphate and calcium during acid-induced gelation.

The rheological properties of acid-induced coagulation of camel and cow milk gels following the addition of calcium chloride (CaCl2) and hydrogen phosphate dehydrate (Na2HPO4*2H2O) were investigated using a dynamic low amplitude oscillatory rheology. For a considered condition, the final values of storage modulus (G') and loss modulus (G″) of camel milk gels were significantly lower than those of cow milk gels. The increase of the added CaCl2 levels improved significantly the gelation properties of camel and cow milk gels, since a reduction in the gelation time and an increase in the gel firmness were observed. Following the addition of Na2HPO4*2H2O at 10 and 20 mM, no significant effect on the gelation rate and the firmness of camel milk gels was observed, while, a significant decrease in the gelation rate and firmness were observed for cow milk gels.

A review on nutritional quality of animal and plant-based milk alternatives: a focus on protein.

In recent years, the demand of consumers for products rich in protein is of significant growth. Due to its structure in tissues, protein is considered an essential nutrient for maintenance and growth. It is well known that dairy foods differ from plant-based milk alternatives in their composition. In addition to protein content, nutrients in milk and plant-based beverages vary greatly in composition and content, such as: Calcium, fiber and fat. The nutritional quality of dairy protein sources depends on both their amino acid composition and bioavailability. Indeed, dairy products are considered to be excellent sources of proteins with high Digestible Indispensable Amino Acid Score (DIAAS) values varying from 100 to 120. However, plant proteins are considered to have generally lower essential amino acid contents and lower DIAAS values than dairy proteins. For example, pea and rice proteins are known to have medium and lower DIAAS with values of 62 and 47, respectively. The present review is dedicated to study the nutritional quality of animal and plant-based milk alternatives, where a focus on protein composition and amount are determined.

Chemical Characterization and Biological Activities Evaluation of Myrtus communis L. Essential Oil Extraction By-Product towards Circular Economy and Sustainability.

Essential oil (EO) extraction is a widespread practice generating huge amounts of solid plant by-products a potential source of bioactive compounds, on the one hand, and a detrimental risk for the environment that needs to be carefully considered on the other hand. The present study aims to valorize Myrtus communis L. leaf by-products obtained following EO extraction using a steam distillation unit through the recovery of phenolic compounds and the evaluation of their biological activities. The total phenols, flavonoids, and proanthocyanidins contents of the ethanolic extract by-product were higher than the control (leaves without extraction of EO). Their amounts increased from 69.30 to 88.06 mg GAE/g for total phenols, from 36.31 to 70.97 mg QE for flavonoids and from 19.74 to 21.49 mg CE/g of extract for proanthocyanidins. The identification of phenolic compounds by high-performance liquid-chromatography equipped with a reversed-phase (RP-HPLC) system revealed that the by-product sample includes more gallic acid, catechin, syringic acid and luteolin 7-O-glucoside but less p-coumaric acid and kaempferol than the control. Moreover, the mid-infrared spectroscopy (MIR) showed the presence of benzene ring characteristic of phenolic compounds at 756 cm-1, esters of aromatic acids and stretching vibrations of polyphenols at 1141-1234 cm-1, C=C stretching present in phenolic acids such as coumaric acid and catechin at 1604 cm-1. The assessment of antioxidant activity revealed that the ABTS+• radical scavenging activity was significantly increased, whereas the DPPH• radical inhibition activity and the ferric reduction antioxidant power were significantly decreased. The results indicated, as well, that Myrtus communis L. leaf by-products maintained a considerable antibacterial activity depending on the tested bacterial strain. Additionally, the anti-α-amylase activity was higher for the Myrtus communis L. leaf by-product extract. Therefore, Myrtus communis L. leaf by-products of EO extraction offer phenolic compounds with significant biological activities, contributing to the sustainable development and the promotion of circular economy by the recovery of valuable inputs from plant by-products.

Impact of pilot-scale microfluidization on soybean protein structure in powder and solution.

The effect of microfluidization treatment on the primary, secondary, and tertiary structure of soybean protein isolate (SPI) was investigated. The samples were treated with and without controlling the temperature and circulated in the system 1, 3, and 5 times at high pressure (137 MPa). Then, the treated samples were freeze-dried and reconstituted in water to check the impact of the microfluidization on two different states: powder and solution. Regarding the primary structure, the SDS-PAGE analysis under reducing conditions showed that the protein bands remained unchanged when exposed to microfluidization treatment. When the temperature was controlled for the samples in their powder state, a significant decrease in the quantities of ß-sheet and random coil and a slight reduction in α-helix content was noticed. The observed decrease in ß-sheet and the increase in ß-turns in treated samples indicated that microfluidization may lead to protein unfolding, opening the hydrophobic regions. Additionally, a lower amount of α-helix suggests a higher protein flexibility. After reconstitution in water, a significant difference was observed only in α-helix, ß-sheet and ß-turn. Related to the tertiary structure, microfluidization increases the surface hydrophobicity. Among all the conditions tested, the samples where the temperature is controlled seem the most suitable.

Impact of storage period and lipid unsaturation on the kinetic of 5-hydroxymethylfurfural and furfural generation in pound cakes.

This work aimed at studying the influence of formulation and storage on the formation of Maillard compounds called 5-hydroxymethylfurfural (HMF) and furfural in pound cakes formulated with rapeseed oil (RO) and palm oil (PO). A progressive humidification of the crust and a dryness of the crumb were observed during storage. Lightness (L*) decreased for both PO and RO pound cakes in crumb as well as crust. The accumulation of HMF was found to be higher in the crust (2.21-38.5 mg kg-1) in comparison with the crumb (0.78 to 10.29 mg kg-1). Similar results were found for furfural where the concentration range was between 0.98 and 5.67 mg kg-1 in the crumb while between 2.1 and 38.39 mg kg-1 in the crust. Thus, the formation of HMF and furfural depended on formulation. The PLS-DA showed a positive correlation between the kinetic of HMF and furfural migration and the storage period.

Development of 2D and 3D front face fluorescence spectroscopy for monitoring ultrasound treatment in the removal of pesticides residues from fresh lettuces at the laboratory and pilot scales.

Pesticide residues in vegetables are potentially toxic components to humans and can cause serious health problems. To remove pesticide residues from fresh agricultural products and improve consumer food safety, various pesticide removal methods have been investigated over the past decades. In this study, the effectiveness of laboratory and pilot scale ultrasonic cleaning on the removal of boscalid and pyraclostrobin residues from lettuce was examined. 2D fluorescence spectroscopy, 3D fluorescence spectroscopy represented by excitation-emission matrix (EEM), and parallel factor analysis (PARAFAC) were used to characterize and discriminate the fluorescence signatures of these pesticides in the cleaning water to determine the effectiveness of the ultrasonic cleaning method as a function of the level of pesticide removal. The 2D fluorescence results showed that the rate of removal of boscalid by ultrasonics at the laboratory scale increased with the cleaning time. The ultrasonic treatment showed a higher cleaning efficiency compared to only soaking in distilled water for 10 min. The same trends were observed at the pilot scale. The EEM also showed differences in the concentration of pesticides removed by ultrasonication between the different parts of the lettuce, the concentration was higher in the upper part than the lower part. This study showed that ultrasonication is an effective technique for the removal of pesticide residues on lettuce, and it also showed the significant potential of fluorescence spectroscopy coupled with PARAFAC for the discrimination and characterization of pesticides.

Variability in the substitution pattern of hydroxypropyl cellulose affects its physico-chemical properties.

Hydroxypropyl cellulose (HPC) is a water-soluble polymer with many applications in food, pharmaceutical, medical, or paints industries. Past studies have reported that differences in functionality can occur between products of similar pharmaceutical grades. Understanding the origin of these differences is a major challenge for the industry. In this work, the structure and physico-chemical properties of several HPC samples of the same commercial grade were studied. Structural analysis by NMR and enzymatic hydrolysis were performed to study molar substitution and distribution of substituents along the polymer chain respectively. Water-polymer interactions, surface properties as well as rheological and thermal behavior were characterized to tentatively correlate them with the structure, and gain new insights into the structure-function relationship of this polymer. The differences in structure revealed between the samples affect their properties. The unexpected behavior of one sample was attributed to a more heterogeneous substitution pattern, with the coexistence of highly and weakly substituted regions along the same polymer chain. The more block-like distribution of substituents has a great effect on the clouding behavior and surface tension reduction ability of the polymer.

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

Two vegetal oils have been selected for the formulation of pound cakes, rapeseed oil (RO) and palm oil (PO). The freshness of these products has been monitored during 58 days of storage. The RO pound cakes of 58 days as well as PO pound cakes presented higher values (p < .05) of hardness (N), Young's modulus (N.cm-2 ) and compressive stress (N.cm-2 ) than those aged of 5 days. For both vitamin A and tryptophan spectra, the maximum of fluorescence intensity varied according to the aging period. For both RO and PO recipes, lipid oxidation indicators (peroxide value, para-anisidine value, and total oxidation value [TOTOX]) were interestingly correlated to Young's modulus (R2  = 0.99) as well as compressive stress (R2  = 0.99), using polynomial model. The application of partial least squares regression to the vitamin A spectra provided excellent predictive results for both compressive stress (R2  = 0.99) and TOTOX (R2  = 0.99). Good results were observed for tryptophan spectra for the prediction of TOTOX (R2  = 0.77). Thus, the use of front face fluorescence spectroscopy may provide rapid and accurate results for the monitoring of pound cakes freshness throughout storage.

Assessing the quality of dry sausages using fluorescence spectroscopy, physico-chemical, and dynamic testing rheology: A preliminary study.

The viscoelastic and the structure properties of three brands of dry sausages (Auvergne, Beef-poultry, and Galbanetto) were studied using dynamic rheology and fluorescence spectroscopy. The storage and the loss modulus of sausage samples showed a viscoelastic character. The principal component analysis carried out on the normalized rheological and physico-chemical parameters allowed to differentiate the sausage samples into three groups according to their brands. This trend was confirmed by the factorial discriminant analysis where 74.44% of correct classification was obtained. The emission spectra acquired after excitation set at 290, 340, and 360 nm and excitation spectra scanned after emission set at 410 nm allowed clear differentiation between the three brand samples. The obtained results were confirmed following the application of partial least squares regression to the fluorescence and physico-chemical parameters since an excellent prediction of moisture content was obtained from the excitation spectra set at 340 nm (R2  = 0.99) and 360 nm (R2  = 0.99). The protein content of dry sausages was well predicted after excitation set at 290 and 340 nm with R2 of 0.96 and 0.97, respectively, while the fat level was well estimated after excitation set at 340 and 360 nm and emission set at 410 nm (R2  = 0.96, 0.96 and 0.94, respectively). The obtained results showed the potential use of fluorescence spectroscopy as a rapid technique for evaluating the quality of dry sausages.