Quality and authenticity control of fruit purées, fruit preparations and jams—a review

Rapid and sensitive approaches for detecting food fraud: A review on prospects and challenges

Precise and reliable analytical techniques are required to guarantee food quality in light of the expanding concerns regarding food safety and quality. Because traditional procedures are expensive and time-consuming, quick food control techniques are required to ensure product quality. Various analytical techniques are used to identify and detect food fraud, including spectroscopy, chromatography, DNA barcoding, and inotrope ratio mass spectrometry (IRMS). Due to its quick findings, simplicity of use, high throughput, affordability, and non-destructive evaluations of numerous food matrices, NI spectroscopy and hyperspectral imaging are financially preferred in the food business. The applicability of this technology has increased with the development of chemometric techniques and near-infrared spectroscopy-based instruments. The current research also discusses the use of several multivariate analytical techniques in identifying food fraud, such as principal component analysis, partial least squares, cluster analysis, multivariate curve resolutions, and artificial intelligence.

Interactions in plasticizer mixtures used for sugar replacement

In our quest for novel ingredients to be used in sugar replacement strategies, we have investigated the thermodynamics of polycarboxylic acids, such as citric acid. We have demonstrated the applicability of the Flory-Huggins (FH) theory to describe the thermodynamics of polycarboxylic acids solutions. Moreover, for citric acid we can describe the complete phase diagram with the theory. It shows that polycarboxylic acids have similar plasticizing and hygroscopic properties as sugars and polyols. Regarding mixtures of polycarboxylic acids and carbohydrates, the FH theory is able to describe a) the water activity of the mixtures, b) the solubility of ternary mixtures of acids and sugars, c) the lowering of the deliquescence point for binary mixtures of crystals, and d) the melting point depression in eutectic mixtures. Unexpectingly, our investigations show there is a strong non-zero FH interaction parameter between carboxylic acids and carbohydrates. In our prior sugar replacement strategy we have assumed zero interactions between plasticizers. Here, we will readdress this assumption. Carefull investigations of solid-liquid equilibrium of eutectic mixtures involving polycarboxylic acids and/or carbohydrates, shows nearly zero interaction in eutectic mixtures consisting only of two carbohydrates or two polycarboxylic acids. We now hold the hypothesis that there is strong non-zero interaction if the mixture contains plasticizers strongly differing in the amount of hydrogen bonding groups. This strong interaction explains why these mixtures, like polycarboxylic acids and carbohydrates, are excellent candidates as deep eutectic solvents. Furthermore, we conclude that polycarboxylic acids are useful additions to the toolbox of sugar replacers, albeit that there are some limitations to their amounts used.

Challenges in Medicinal and Aromatic Plants DNA Barcoding-Lessons from the Lamiaceae

The potential value of DNA barcoding for the identification of medicinal plants and authentication of traded plant materials has been widely recognized; however, a number of challenges remain before DNA methods are fully accepted as an essential quality control method by industry and regulatory authorities. The successes and limitations of conventional DNA barcoding are considered in relation to important members of the Lamiaceae. The mint family (Lamiaceae) contains over one thousand species recorded as having a medicinal use, with many more exploited in food and cosmetics for their aromatic properties. The family is characterized by a diversity of secondary products, most notably the essential oils (EOs) produced in external glandular structures on the aerial parts of the plant that typify well-known plants of the basil (Ocimum), lavender (Lavandula), mint (Mentha), thyme (Thymus), sage (Salvia) and related genera. This complex, species-rich family includes widely cultivated commercial hybrids and endangered wild-harvested traditional medicines, and examples of potential toxic adulterants within the family are explored in detail. The opportunities provided by next generation sequencing technologies to whole plastome barcoding and nuclear genome sequencing are also discussed with relevant examples.

The chemical composition of two kinds of grape juice with medicinal plant addition

The safety of plant-based food with an herbal origin is a priority for producers and final consumers these days. The interest in the high biological value of the final food products enriched with herbal ingredients is rising. We focused on the study of physico-chemical composition and antioxidant activity of two kinds of grape juice with medicinal plant addition in our study. We used 2 varieties of grapes - Welschriesling and Cabernet Sauvignon, six species of medicinal plants - Calendula officinalis L., Ginkgo biloba, Thymus serpyllum, Matricaria recutita, Salvia officinalis L., and Mentha aquatica var. citrata in our experiment. There were14 samples prepared, two of them were control samples and 12 samples were treated with medicinal plants. We tested each of the selected parameters triplicate with an interval of one week. We evaluated the results statistically in 4 levels of significance p <0,01, p <0,001, p <0,0001 and p <0,00001. The content of fructose, glucose, dry matter, density, malic acid, pH, potential alcohol, total acids, and total sugars in the treated samples was significantly lower compared to the control sample, which was probably due to the degree of dilution of grape juice with extracts gained from medicinal plants. The antioxidant effect was demonstrably higher in the samples enriched with medicinal plants than in the control samples. The highest antioxidant effect was measured in the second test in the samples with the addition of Thymus serpyllum (80.93 % - white grape must, 82.33 % - blue grape must), Calendula officinalis L. (79.29 % - white grape must, 80.49 % - blue grape must) and Ginkgo biloba (79.10 % - white grape must, 83.3 % - blue grape must). Generally, we found out that the selected medicinal plants increase the biological quality of grape juice.

A microfluidic viscometer: Translation of oscillatory motion of a water microdroplet in oil under electric field

The electric field induced motion of a charged water droplet suspended in a low-dielectric oil medium is exploited to evaluate the rheological properties of the suspending medium. The time-periodic electrophoretic motion of the droplet between the electrodes decorated in a polymeric micro-well is translated into a proof-of-concept microfluidic prototype, which can measure viscosities of the unknown fluid samples. The variations in the instantaneous velocities of the migrating droplet have been measured inside silicone oil of known physical properties at different electric field intensities. Subsequently, a balance between the electric field to the viscous force has been employed to evaluate the experimental charge density on the droplet surface. Thereafter, a comprehensive scaling law has been devised to find a correlation between the charge on the droplet to the dielectric permittivity of the surrounding medium, size of the water droplet, and the applied electric field intensity. Following this, the scaling law and force balance have been employed together to evaluate the unknown viscosity of an array of suspending mediums by simply analyzing the electrophoretic motion of water droplet. The model proposed is also found to be consistent when a solid amberlite microparticle has been employed as a probe instead of the water droplet. In such a scenario, minor changes in the exponents of the scaling law are found to be necessary to reproduce the results obtained using the water droplet. The method paves the way for the making of an economical and portable microfluidic rheometer with further finetuning and translational developments.

Detection of the Freshness of Kiwifruit with a TD-GC-MS and a Gas-sensing Array Based on the Surface-acoustic-wave Technique

An electronic nose is an arrayed gas sensor mimicking the human olfactory system that can analyze and identify a flavour on collecting an odour from an environment. In our experiments, an electronic-nose system based on a surface acoustic wave (SAW) was used to measure the freshness of kiwifruit. 128° YX-LiNbO3 acted as a piezoelectric material; Au was deposited as an electrode and sensing area. With a polymer coating of various types on the sensing area and a connection to an oscillator circuit, a 113-114 MHz SAW was obtained. Depending on the properties of varied polymers, the frequency shift varied due to absorbed volatile organic compounds (VOC). In this way, with four surface-acoustic-wave sensors coated with varied polymers we built a kiwi-flavour database according to results from a TD-GC-MS system. When the concentration of esters increased, the kiwifruit began to ripen, accompanied by increased concentrations and types of VOC. As a result, polystyrene (PS) and fluoropolymer (CYTOP) polymers, which played the role of sensing materials, served as major materials to determine the ester aroma profile. Polyvinyl alcohol (PVA), polyvinyl butyral (PVB) and poly-N-vinylpyrrolidone (PNVP) were used to trap the alcohols and acids during a kiwifruit ripening period. This research proved that discrimination of differences is feasible from an unripe stage to a ripe stage and from a ripe stage to an over-ripe stage.

Mid-infrared technique to forecast cooked puree properties from raw apples: A potential strategy towards sustainability and precision processing

The potential of MIRS was investigated to: i) differentiate cooked purees issued from different apples and process conditions, and ii) predict the puree quality characteristics from the spectra of homogenized raw apples. Partial least squares (PLS) regression was tested both, on the real spectra of cooked purees and their reconstructed spectra calculated from the spectra of homogenized raw apples by direct standardization. The cooked purees were well-classified according to apple thinning practices and cold storage durations, and to different heating and grinding conditions. PLS models using the spectra of homogenized raw apples can anticipate the titratable acidity (the residual predictive deviation (RPD) = 2.9), soluble solid content (RPD = 2.8), particle averaged size (RPD = 2.6) and viscosity (RPD ≥ 2.5) of cooked purees. MIR technique can provide sustainable evaluations of puree quality, and even forecast texture and taste of purees based on the prior information of raw materials.

DNA barcoding: a modern age tool for detection of adulteration in food

Globalization of the food trade requires precise and exact information about the origin, methods of production, transformation technologies, authentication, and the traceability of foodstuffs. New challenges in food supply chains such as deliberate fraudulent substitution, tampering or mislabeling of food and its ingredients or food packaging incapacitates the market and eventually the national economy. Currently, no proper standards have been established for the authentication of most of the food materials. However, in order to control food fraud, various robust and cost-effective technologies have been employed, like a spectrophotometer, GC-MS, HPLC, and DNA barcoding. Among these techniques, DNA barcoding is a biotechnology advantage with the principle of using 400-800 bp long standardized unique DNA sequences of mitochondrial (e.g. COI) or plastidial (e.g. rbcL) of nuclear origin (e.g. ITS) to analyze and classify the food commodities. This review covers several traded food commodities like legumes, seafood, oils, herbal products, spices, fruits, cereals, meat, and their unique barcodes which are critically analyzed to detect adulteration or fraud. DNA barcoding is a global initiative and it is being accepted as a global standard/marker for species identification or authentication. The research laboratories and industries should collaborate to realize its potential in setting standards for quality assurance, quality control, and food safety for different food products.

The effect of storage on the quality parameters of baby food

The aim of this paper was focused on the quality changes of baby food stored at different temperature (4 °C, 20 °C, 40 °C and 60 °C) for 15 days. During storage, chemical and nutritional parameters analysis were carried out. Commercial fruits based baby food are the products usually made with fruits, sugar, and variable additives. As the foodstuffs intended for particular nutritional uses, baby foods for infants and young children conform to a set of strict guidelines e.g. nutritional quality, the addition of additives, labeling. However, being an important supplement to children‘s diet and for their progressive adaptation to ordinary food, the nutritional quality of commercial fruits baby food is very important. Samples of commercial fruits baby food from the market and pharmacies were analyzed by parameters: pH, total soluble solids, moisture, total acidity, vitamin C, proteins, sugars, and lipids. All samples of baby food are produced by foreign companies since currently, no Kosovo manufacturers are producing this range of products. The nutritional quality parameters are important to assess the quality of the product and how it can be safely stored. However, as a precaution, storage remarks in the product labels should always be followed.

Profiles of Sugar and Organic Acid of Fruit Juices: A Comparative Study and Implication for Authentication

A comparison of sugar and organic acid profiles among different fruit juices (including apple, pear, peach, grape, sweet cherry, strawberry, and blueberry with various varieties) was performed to assess the possibility for authentication coupled with chemometrics. It was found that the distribution of each sugar and organic acid in juices showed some specific characteristics related to fruit species, despite the fact that great differences in the content existed among different varieties. Sucrose was the most abundant sugar in peach juice, accounting for 58.26–77.11% of the total sugar content. However, in grape, blueberry, and sweet cherry juice, glucose and fructose were the predominant sugars. Pear juice contained the highest level of sorbitol, which contributed to 15.02–43.07% of the total sugar content. Tartaric acid was detected only in grape juice among the seven species of fruit juice, with a proportion of 57.95–89.68% in the total acid content. Malic acid was the predominant organic acid in apple and sweet cherry juice, accounting for 69.92–88.30% and 97.51–98.73% of the total acid content of each species. Citric acid was the predominant organic acid in strawberry and blueberry juice, which contributed to 62.39–83.73% and 73.36–89.56% of the total acid content of each species. With the aid of principal component analysis and linear discriminant analysis (LDA), the juice samples could be successfully classified according to fruit species by using the sugar and/or organic acid composition as analytical data. Combination of sugar and organic acid composition gave the best differentiation of these seven species of juices, with a 100% correct classification rate for both the original and the cross-validation method in LDA. Adding malic/citric into the dataset of the organic acid content may also improve the differentiation effect. Furthermore, the adulteration of sweet cherry juice, blueberry juice, raspberry juice, and grape juice with apple juice, pear juice, or peach juice could also be distinguished from their corresponding pure juices based on sugar and organic acid composition by LDA.

Phenolic Compounds in Poorly Represented Mediterranean Plants in Istria: Health Impacts and Food Authentication

Phenolic compounds are well-known bioactive compounds in plants that can have a protective role against cancers, cardiovascular diseases and many other diseases. To promote local food development, a comprehensive overview of the phenolic compounds' composition and their impact on human health from typical Mediterranean plants such as Punica granatum L., Ziziphus jujuba Mill., Arbutus unedo L., Celtis australis L., Ficus carica L., Cynara cardunculus var. Scolymus L. is provided. Moreover, the potential use of these data for authenticity determination is discussed. Some of the plants' phenolic compounds and their impact to human health are very well determined, while for others, the data are scarce. However, in all cases, more data should be available about the content, profile and health impacts due to a high variation of phenolic compounds depending on genetic and environmental factors. Quantifying variation in phenolic compounds in plants relative to genetic and environmental factors could be a useful tool in food authentication control. More comprehensive studies should be conducted to better understand the importance of phenolic compounds on human health and their variation in certain plants.

Development of an FTIR based chemometric model for the qualitative and quantitative evaluation of cane sugar as an added sugar adulterant in apple fruit juices

A Fourier Transform Infrared Spectroscopy based chemometric model was evaluated for the rapid identification and estimation of cane sugar as an added sugar adulterant in apple fruit juices. For all the ninety samples, spectra were acquired in the mid-infrared range (4000 cm^-1-400 cm^-1). The spectral analysis provided information regarding the distinctive variable region, which lies in the range of 1200cm^-1 to 900cm^-1, designated as fingerprint region for the carbohydrates. A specific peak in the fingerprint region was observed at 997cm^-1 in all the adulterated samples and was undetectable in pure samples. Based on different levels of cane sugar adulteration (5, 10, 15, and 20%), principal component analysis showed the clustering of samples and further helped us in compression of data by selecting wavenumbers with maximum variability based on the loading line plot. Supervised classification methods (SIMCA and LDA) were evaluated based on their classification efficiencies for a test set. Though SIMCA showed 100% classification efficiency (Raw data set), LDA was able to classify the test set with an accuracy of only 96.67% (Raw as well as Transformed data set) between pure and 5% adulterated samples. For the quantitative estimation, calibration models were developed using partial least square regression (PLS-R) and principal component regression method (PCR) methods. PLS-1^st derivative showed a maximum coefficient of determination (R²) with a value of 0.991 for calibration and 0.992 for prediction. The RMSECV, RMSEP, LOD and LOQ observed for PLS-1^st derivative model were 0.75% w/v, 0.61% w/v, 1.28%w/v and 3.88%w/v, respectively. The coefficient of variation as a measure of precision (repeatability) was also determined for all models, and it ranged from 0.23% to 1.83% (interday), and 0.25% to 1.43% (intraday).

Color stability of fruit yogurt during storage

This article describes the evaluation of the anthocyanins stability in yogurts with strawberry, sour cherry, and blueberry fruit preparation during 8-week storage period under refrigerated condition. The differences in anthocyanin degradation rate and color changes between stirred yogurts and fruit-on-the-bottom yogurts (fruit preparation was on-the-bottom of package) were compared. Anthocyanin content in fruit yogurts showed a significant decreased during the storage, especially for the first 2 weeks. There were differences in the rate of pigment degradation between yogurt obtained from a different species of fruit. The half-life of the pigments in stirred yogurt with the preparation of strawberry, sour cherry, and blueberry was found to be 5.5, 6.7, and 19.0 weeks, respectively. The addition of fruit preparation on the bottom of yogurt could be used to reduce the pigment degradation during storage. The half-life of anthocyanin in fruit-on-the-bottom yogurts was 39-63% higher than in the blending samples. A significant alteration in the pigment profile during storage of blueberry yoghurt was observed. The proportion of malvidin-glucosides and acylated anthocyanins increased with time of storage, with a concomitant decrease in proportion of petunidin, delphinidin and peonidin derivatives.

Distribution of elements in seeds of some wild and cultivated fruits. Nutrition and authenticity aspects

BACKGROUND

The compositional, functional, and nutritional properties of fruits are important for defining their quality. Fruit seeds should be better exploited as they are also considered to be a good source of bioactive components. Twenty macro, micro, and trace elements were identified and quantified in the seeds of 70 genuine wild and cultivated fruit species/cultivars by inductively coupled plasma atomic emission spectrometry and inductively coupled plasma mass spectrometry. Sophisticated chemometric techniques were also used to establish criteria for the classification of the analyzed samples.

RESULTS

Calcium and P were the most abundant elements, followed by K and Na. The content of microelements and trace elements differed among the different cultivars/genotypes. The content of Ba, Pb, and Sr was significantly higher in wild fruits, whereas Fe, Mg, Mn, Ni and Zn content was higher in cultivated fruits.

CONCLUSION

All of the statistical procedures that were used - Kruskal-Wallis, Mann-Whitney U-test, and principal component analysis (PCA) - confirm a unique set of parameters that could be used as phytochemical biomarkers to differentiate fruit-seed samples belonging to different cultivars/genotypes according to their botanical origin. This kind of investigation may contribute to intercultivar/genetic discrimination and may enhance the possibilities of acquiring a valuable authenticity factor. © 2018 Society of Chemical Industry.

Assessing Nutritional Traits and Phytochemical Composition of Artisan Jams Produced in Comoros Islands: Using Indigenous Fruits with High Health-Impact as an Example of Biodiversity Integration and Food Security in Rural Development

In the Comoros Islands, as in other developing countries, malnutrition and food insecurity affect a very large percentage of the population. Developing fruit-based products in order to make profit, reduce poverty and improve indigenous people diet could be very important for local population of countries as Comoros Islands. The aim of the present work was to study the chemical composition of jams and jellies produced from seven fruit species harvested in Grand Comore Island. The following parameters were studied sugars and organic acids, total phenolics, total anthocyanins and high-performance liquid chromatography (HPLC) fingerprint of the main phytochemicals. Antioxidant activity was also measured. A multivariate approach (Principal Component Analysis) was performed in order to better characterize the products and to set a potential analytical tool for jam characterisation. Results showed that the analysed products are a good source of polyphenolic constituents, as caffeic and gallic acids, catechin and quercetin and volatile compounds, as limonene and γ-terpinene: these molecules may be considered as suitable markers for these fruit-derived products as characterizing the chromatographic patterns. The characterisation of these products and their nutritional and nutraceutical traits is important as valorisation of local food production for poverty reduction and rural development. Further benefits of this approach include the maintenance of local agro-biodiversity as raw material for fruit-based products and the strengthening of food security practices.

Detection and Quantitation of Frauds in the Authentication of Cranberry-Based Extracts by UHPLC-HRMS (Orbitrap) Polyphenolic Profiling and Multivariate Calibration Methods

UHPLC-HRMS (Orbitrap) polyphenolic profiling was applied to the characterization, classification, and authentication of cranberry-based natural and pharmaceutical products. Fifty three polyphenolic standards were characterized to build a user-accurate mass database which was then proposed to obtain UHPLC-HRMS polyphenolic profiles by means of ExactFinder software. Principal component analysis results showed a good sample discrimination according to the fruit employed. Regarding cranberry-based pharmaceuticals, discrimination according to the presentation format (syrup, sachets, capsules, etc.) was also observed due to the enhancement of some polyphenols by purification and preconcentration procedures. Procyanidin A2 and homogentisic, sinapic, veratric, cryptochlorogenic, and caffeic acids showed to be important polyphenols to achieve cranberry-based products discrimination against the other studied fruits. Partial least-squares regression allowed the determination of adulterant percentages in cranberry-fruit samples. Very satisfactory results with adulteration quantification errors lower than 6.0% were obtained even at low adulteration levels.

3D-Printed Capillary Circuits for Calibration-Free Viscosity Measurement of Newtonian and Non-Newtonian Fluids

Measuring viscosity is important for the quality assurance of liquid products, as well as for monitoring the viscosity of clinical fluids as a potential hemodynamic biomarker. However, conventional viscometers and their microfluidic counterparts typically rely on bulky and expensive equipment, and lack the ability for rapid and field-deployable viscosity analysis. To address these challenges, we describe 3D-printed capillary circuits (3D-CCs) for equipment- and calibration-free viscosity measurement of Newtonian and non-Newtonian fluids. A syringe, modified with an air chamber serving as a pressure buffer, generates and maintains a set pressure to drive the pressure-driven flows of test fluids through the 3D-CCs. The graduated fluidic chambers of the 3D-CCs serve as a flow meter, enabling simple measurement of the flow rates of the test fluids flowing through the 3D-CCs, which is readable with the naked eye. The viscosities of the test fluids can be simply calculated from the measured flow rates under a set pressure condition without the need for peripheral equipment and calibration. We demonstrate the multiplexing capability of the 3D-CC platform by simultaneously measuring different Newtonian-fluid samples. Further, we demonstrate that the shear-rate dependence of the viscosity of a non-Newtonian fluid can be analyzed simultaneously under various shear-rate conditions with the 3D-CC platform.

A Combined Approach of Infrared Spectroscopy and Multivariate Analysis for the Simultaneous Determination of Sugars and Fructans in Strawberry Juices During Storage

In this work, a Fourier transform mid-infrared spectroscopy (FTIR)-based method was developed for simultaneously quantifying simple sugars and exogenously added fructooligosaccharides (FOS) in strawberry juices preserved for up to 14 d using nonthermal techniques (geraniol and vanillin+ultrasound). The main spectral differences were observed in the 1200 to 900 cm^-1 region. The presence of FOS was identified by the typical bands at 1134, 1034, and 935 cm^-1 . During storage, a significant decrease of sucrose was concomitant to an increase of glucose and fructose in juices stored without any previous preservation treatment, as determined by high-performance liquid chromatography (HPLC). A principal component analysis was performed on the FTIR spectra corresponding to the different treatments. The groups observed explained more than 94% of the variance and were related to changes in the carbohydrate composition during storage. Then, different partial least square models (PLS) were defined to determine the concentrations of glucose, sucrose, fructose, and those of exogenously added FOS with degrees of polymerization within 3 and 5. The carbohydrates' concentrations determined by HPLC were used as reference method. The models were validated with independent sets of data. The mean of predicted values fitted nicely those obtained by HPLC (correlation and R²  > 0.97), thus supporting the use of the PLS models to monitor the quality of strawberry juices in unknown samples. In conclusion, FTIR spectroscopy appears as an adequate analytical tool to quick assess whether juice formulations meet specifications in terms of authenticity, contamination and/or deterioration.

PRACTICAL APPLICATION

FTIR spectroscopy provided a method potentially transferable to the food industry when associated with the multivariate analysis. The robust 21 PLS models defined in this work provided reliable tools for the rapid monitoring of juices' authenticity and/or deterioration. In this regard, FTIR associated to multivariate analysis enabled the determination of different sugars in a single measurement without the need of pure sugars as standards. This experimental simplicity supports the use of FTIR at the production line, and also contributes to save time in determining carbohydrates' composition and stability, in an environmentally friendly way.

Influence of fruit juice processing on anthocyanin stability

Anthocyanins are quality determining compounds in red fruits and their corresponding juices. The fate of anthocyanins during production of juices is determined by countless factors and all of these need to be taken into consideration to optimize juice processes. Storage and pre-press procedures like freezing and thawing may influence the fruit's integrity and accordingly affects the extraction of valuable components during the subsequent mashing and pressing. Conventional thermal or novel non-thermal treatments to ensure microbial safety have both positive and negative effects on the anthocyanins. By inactivation of oxidizing enzymes, profiles and quantities of anthocyanins may be maintained, but more severe conditions may have adverse effects. To improve juice extraction and to increase yield, enzyme-assisted degradation of the cell walls is conducted. The applied enzyme preparations contain numerous side activities which also may degrade anthocyanins. Clarification and concentration will further reduce the final anthocyanin concentrations. Many studies have been published regarding evaluating individual fruits or single processing steps but, obviously, these results are not necessarily transferable. Accordingly, this review aims to summarize all relating studies comprehensively to the fate of anthocyanins during juice processing giving an overview of underlying mechanisms as well as the chemical and analytical background.

Polyphenol patterns to trace sweet (Prunus avium) and tart (Prunus cerasus) varieties in cherry jam

The aim of this work was to assess whether the characteristic polyphenol traits of cherry biotypes persisted in thermally processed cherry products, such as jam. Thus, the RP-HPLC-diode array detector profiles of both colorless polyphenols and anthocyanins from three cherry varieties (two sweet and one tart cherry) were compared with those of low-sugar jam sourced from the same cultivars. Individual components were characterized by mass spectrometry. The total phenolic and total anthocyanin content as well as the radical scavenging potential (residual 75-91, 88-91 and 73-75%, respectively) were only slightly reduced by deep thermal treatments. Apart from the interconversion among the isomers of chlorogenic acid, the profile of both colorless polyphenols and anthocyanins substantially survived the jam manufacturing under conventional temperature-time regimen (80 °C, 1 h). The species- and cultivar-specific polyphenol molecular asset, especially the anthocyanin pattern, has potential to be monitored for traceability purpose, aimed to the varietal assessment of cherry biotypes used for producing jam.

Influence of Accelerated Solvent Extraction and Ultrasound-Assisted Extraction on the Anthocyanin Profile of Different Vaccinium Species in the Context of Statistical Models for Authentication

Anthocyanins are frequently discussed as marker compounds for fruit product authenticity. Proper analysis including sample preparation for the determination of anthocyanin concentrations is crucial for the comparability of authenticity data. The present study determined the influence of accelerated solvent extraction (ASE) and ultrasound-assisted extraction (UAE), using two different solvent compositions on the anthocyanin profile of bilberries (Vaccinium myrtillus L.), lowbush blueberries (Vaccinium angustifolium Ait.), and American cranberries (Vaccinium macrocarpon Ait.). Besides differences in total anthocyanin concentrations in the extracts, significant deviations (p ≤ 0.05) in the individual anthocyanin concentration were observed, resulting in differing anthocyanin proportions. Linear discriminant analysis comparing the differences caused by the extraction method to the natural differences within a set of 26 bilberry and lowbush blueberry samples of different origins was conducted. It revealed that profile variations induced by the extraction methods are in a similar scale to profile variations as a result of geographic and climatic differences.

Rapid differentiation of commercial juices and blends by using sugar profiles obtained by capillary zone electrophoresis with indirect UV detection

A method for the determination of sugars in several fruit juices and nectars by capillary zone electrophoresis with indirect UV-vis detection has been developed. Under optimal conditions, commercial fruit juices and nectars from several fruits were analyzed, and the sugar and cyclamate contents were quantified in less than 6 min. A study for the detection of blends of high-value juices (orange and pineapple) with cheaper alternatives was also developed. For this purpose, different chemometric techniques, based on sugar content ratios, were applied. Linear discriminant analysis showed that fruit juices can be distinguished according to the fruit type, juice blends also being differentiated. Multiple linear regression models were also constructed to predict the adulteration of orange and pineapple juices with grape juice. This simple and reliable methodology provides a rapid analysis of fruit juices of economic importance, which is relevant for quality control purposes in food industries and regulatory agencies.

Impact of gluconic fermentation of strawberry using acetic acid bacteria on amino acids and biogenic amines profile

This paper studies the amino acid profile of beverages obtained through the fermentation of strawberry purée by a surface culture using three strains belonging to different acetic acid bacteria species (one of Gluconobacter japonicus, one of Gluconobacter oxydans and one of Acetobacter malorum). An HPLC-UV method involving diethyl ethoxymethylenemalonate (DEEMM) was adapted and validated. From the entire set of 21 amino acids, multiple linear regressions showed that glutamine, alanine, arginine, tryptophan, GABA and proline were significantly related to the fermentation process. Furthermore, linear discriminant analysis classified 100% of the samples correctly in accordance with the microorganism involved. G. japonicus consumed glucose most quickly and achieved the greatest decrease in amino acid concentration. None of the 8 biogenic amines were detected in the final products, which could serve as a safety guarantee for these strawberry gluconic fermentation beverages, in this regard.

Nucleotide based validation of Ocimum species by evaluating three candidate barcodes of the chloroplast region

The genus Ocimum comprises of several medicinally important species which frequently fall prey to adulteration due to misidentification. A proficient method is hence required to solve the problems that exist in differentiating its various morphotypes. In plants, candidate DNA barcodes of the chloroplast and nuclear regions have proved to be a great success in the validation of several plant families. Hence, this study involves the use of the molecular-based DNA barcoding method to identify some of the most common and useful species of the genus Ocimum (Tulsi). Here, DNA amplification of three candidate barcodes of the chloroplast genome viz. matK, rbcL and psbA-trnH was performed, to access their ability to produce high sequence variability. The discrimination among species was performed using the Kimura 2-parameter and maximum composite likelihood methods. On analysing the sequence data, the psbA-trnH region proved to be the most suitable candidate barcode and gave an overall variation of 7.3% at the interspecies level. A clear differentiation was found at the species level, showing a maximum distance of 0.264 between dissimilar species. Also, phylogenetic analysis led to the successful identification of hybrids, while it failed to do so at the variety level. Hence, it can be inferred that DNA barcoding is ideal for species-level identification of the genus Ocimum.

Survey of South African fruit juices using a fast screening HILIC-MS method

Adulteration of fruit juices--by the addition of sugar or other less expensive fruit juices as well as preservatives, artificial sweeteners and colours--was tested for by using a developed screening method. The method employs hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-MS) using electrospray ionisation in the negative mode and ultraviolet light detection. Different fruit juices can be differentiated by the content of marker compounds like sorbitol, certain phenolic molecules and their saccharide profile. This method was used to test 46 fruit juice samples from the retail market as well as 12 control samples. The study focused on the main types of fruit juices consumed on the South African market including apple, orange, grape and blends of these juices with other fruits like mango, pear and guava. Overall, the 46 samples tested mostly agreed with label claims. One grape juice sample was adulterated, probably with apple juice. Natamycin above the legal limits was found in two samples. In addition, two samples contained natamycin and one sample benzoate without it being indicated on the label. The method is well suited as a quick screening method for fruit juice adulteration and if used routinely would reduce fruit juice adulteration without the cost of the current array of tests needed for authenticity testing.

A Review of Optical Nondestructive Visual and Near-Infrared Methods for Food Quality and Safety

This paper is a review of optical methods for online nondestructive food quality monitoring. The key spectral areas are the visual and near-infrared wavelengths. We have collected the information of over 260 papers published mainly during the last 20 years. Many of them use an analysis method called chemometrics which is shortly described in the paper. The main goal of this paper is to provide a general view of work done according to different FAO food classes. Hopefully using optical VIS/NIR spectroscopy gives an idea of how to better meet market and consumer needs for high-quality food stuff.

Comparing procyanidins in selected Vaccinium species by UHPLC-MS(2) with regard to authenticity and health effects

Cranberry procyanidins have been associated with an effect against urinary tract infections (UTI) for decades, and European health claims are requested. This study compares the procyanidin profiles and concentrations of American cranberry ( Vaccinium macrocarpon Ait.), European cranberry ( Vaccinium oxycoccus L.), and lingonberry ( Vaccinium vitis-idaea L.) analyzed using ultrahigh-performance liquid chromatoraphy coupled to a triple-quadrupole mass spectrometer with electrospray interface (UHPLC-MS(2)). Concentrations of A-type trimers, procyanidin A2, catechin, epicatechin, and B-type dimers and trimers have been evaluated and compared for the first time in the three berries. The data clearly show remarkable differences in the procyanidin profiles and concentrations, especially the lack of A-type trimers in V. oxycoccus; thus, the effectiveness against UTI may vary among the Vaccinium species. These differences can be used to prove authenticity.