Commercial Puree Research Articles

Rheological, functional properties, and stability of peach puree added with normal and high amylose retrograded starches

ABSTRACT Texture-modified foods have become a growing trend in the market and retrograded starch can enhance the rheological properties of foods. This study assessed the effect of adding 10% (w/w) of normal (RNS) or high amylose (RHS) retrograded starches on the physicochemical and rheological properties of commercial peach puree stored at 4°C. The resistant starch content (RS), syneresis, and rheological behavior were evaluated during 14-day storage. Control puree exhibited high syneresis (60%), low consistency (6 Pa·sn), and decreasing viscosity during storage. These characteristics improved after adding retrograded starches. Samples with RNS exhibited higher viscosity, lower syneresis, lower RS (2%), and poor stability; meanwhile, the systems with RHS exhibited greater stability maintaining their viscosity, syneresis, and RS (10%) relatively constant during storage. Therefore, RHS can be recommended to enhance and maintain the physicochemical, nutraceutical, and rheological properties of a food matrix like peach puree during storage.

NADES-assisted sample preparation as a greener alternative for mycotoxins determination in apple-based products

While impressive advancements have been reported in mycotoxin analysis over the last decade, very little has been done to realign the sample treatment to the green sample preparation principles, which are arising more and more relevance in the current analytical chemistry. In this regard, this work proposes the first NADES-assisted sample preparation for the extraction of mycotoxins in food samples.Two protocols using dispersive liquid–liquid microextraction (DLLME) and DLLME with solidification of floating organic drop (DLLME-SFO) assisted with a natural deep eutectic solvent (NADES) were developed and assessed as green sample preparation procedures to extract mycotoxins from apple-based products prior to HPLC-MS/MS analysis. The selected mycotoxins were alternariol, alternariol monomethyl ether, tentoxin and ochratoxin A, which are known to occur in these food matrices. The main variables affecting the extraction efficiency, such as volume of dispersive and extraction solvents, as well as the salting-out effect were evaluated and optimized using a central composite design. In addition, both methodologies were examined and compared in terms of greenness using the newly released metric tool AGREEprep. Due to the use of NADES, the DLLME-SFO method achieved a higher greenness score, and it was selected for further characterization. Matrix-matched calibration curves were used, showing a satisfactory linearity (R2 > 0.99). Limits of detection (LODs) and quantification (LOQs) were below 0.25 and 0.8 µg kg−1, respectively. Recoveries were above 72 % for all the mycotoxins studied in both apple juice and apple puree samples. The validated DLLME-SFO-HPLC-MS/MS method was applied to the analysis of commercial apple juice and puree samples. All the samples analysed were contaminated with at least one mycotoxin with a total concentration ranging from 0.4 to 10.5 µg kg−1.

Cytoprotective and Antigenotoxic Properties of Organic vs. Conventional Tomato Puree: Evidence in Zebrafish Model

In this in vivo study, we investigated cytoprotective and antigenotoxic effects of commercial tomato puree obtained from conventional vs. organic farming systems (pesticides vs. pesticide-free agriculture, respectively). This is relevant as pesticides are widely used in agriculture to prevent pests, weeds, and the spread of plant pathogens. By exposing zebrafish to tomato puree alone and in combination with H2O2 (a well-known genotoxic agent), we analyzed the percentage of fish survival, cell viability, intracellular concentration of reactive oxygen species (ROS), DNA fragmentation index (DFI%), and genomic template stability (GTS%). Fish exposed to organic puree showed higher fish survival and cellular viability, lower DFI% and ROS, and improved GTS%. Our results suggest a higher cytoprotective and antigenotoxic effect of organic pesticide-free tomatoes, probably because the activity of natural phytochemicals is not affected by the presence of toxic residues, which are otherwise produced by pesticides used in conventional farming systems. Our study points out the importance of considering alternative strategies in agriculture to minimize the genotoxic impact of chemical pesticides.

Structural characterization of red beet fiber and pectin

Detailed composition, fine structure, and functional relationships of multiple red beet fiber fractions were determined. Red beet pomace, the fraction remaining after commercial puree extraction, contained dietary fiber (50.8%), that was largely insoluble (40.1% vs. 10.7% soluble dietary fiber) with pectin as the major polysaccharide; sucrose (8.07%), fructose (1.14%) and glucose (2.33%) free sugars; protein (10.2%), and fat (3.02%). Malto-oligosaccharides and methyl-esterified, acetylated and feruloylated rhamnogalacturonan I oligosaccharides with branched arabinogalacto-oligosaccharide side chains were detected by MALDI-TOF MS and NMR analysis. Red beet pectin, acid-extracted with a microwave using 10 min and 80 °C conditions, had high molar mass (1036 kDa) with viscosity that was similar to sugar beet pectin extracted under the same conditions. A random coil shape was confirmed for red beet pectin microwave extracted under 3 min and 120 °C conditions. Longer microwave extraction times and microwave extraction at pH 1 produced compact spherical red beet pectin with lower molar mass and viscosity. The structural properties of these red beet pomace and fiber fractions suggest that they can function to thicken and stabilize food systems, and the structure of the pectin fractions indicate strong potential as a prebiotic food ingredient.

Structure and composition of blueberry fiber pectin and xyloglucan that bind anthocyanins during fruit puree processing

Blueberry is a well-known source of antioxidants and prebiotic dietary fiber yet the fate of these health-beneficial ingredients during fruit processing it is not understood. Detailed composition and structure of blueberry pomace (PF) remaining after commercial blueberry fruit puree processing, as well as the water soluble and water insoluble fractions, were determined. The PF was comprised of dietary fiber (60.8%) that was largely insoluble (46.2% vs. 14.6% soluble dietary fiber) pectin, xyloglucan, arabinoxylan and mannan polysaccharides, fructose (11.22%) and glucose (10.37%) free sugars, protein (9%), fat (5%), and anthocyanins (6444.5 μg/g). The most abundant anthocyanins detected in PF were malvidin 3-arabinoside and peonidin 3-glucoside and the pectin was determined to be methyl-esterified and acetylated rhamnogalacturonan I with a 4,5-unsaturated function at the non-reducing end based on oligosaccharide structural analysis. Blueberry PF xyloglucan oligosaccharide side chain structures included xylose, arabinose and galactose consistent with arabino-xyloglucan structure. Microwave-assisted extraction of blueberry PF (pH 2 for 10 min at 80 °C) was performed to more clearly elucidate pectin structure, and revealed a pectin polymer with high molar mass (1072 kDa) and viscosity that was dependent upon the molar mass. A random coil shape was confirmed for both the blueberry PF and microwave extracted blueberry pectin, which agreed with previous reports that flexible blueberry pectin contributes to strong anthocyanin binding. In summary, the blueberry pomace anthocyanin content was slightly higher than that reported for fresh whole blueberry fruit, which suggests that most blueberry anthocyanins adhered to the pomace fiber, and most likely the insoluble pectin, during and after processing.

Assessing the microstructural and rheological changes induced by food additives on potato puree

The effects of agar, alginate, lecithin and glycerol on the rheological properties of commercial potato puree were investigated and interpreted in terms of starch microstructural changes, and the applicability of the Cox-Merz rule was evaluated. Each additive was applied separately at two concentrations (0.5 and 1%). Microscopic observations revealed more swollen starch aggregations in lecithin and glycerol compared with those of potato puree and agar, consequently affecting the rheological properties of potato puree. All samples exhibited shear thinning non-Newtonian behaviour. Rheological measurements were strongly concentration dependent. At 0.5% concentration, additives exerted decreases in all the rheological properties of potato puree in the order of glycerol>alginate>lecithin>agar, while at 1% concentration, the order changed to glycerol>lecithin>alginate, whereas 1% agar behaved differently, increasing all rheological values. This study also showed that agar and alginate in addition to potato puree could be valuable and advantageous for further technological processes, such as 3D printing.

The effects of banana ripeness on quality indices for puree production

The physical and chemical compositional changes of Cavendish bananas were investigated according to the ripening stages determined by peel colour as classified in the Banana Ripening Guide. There is a need for the utilization of second grade bananas that are deemed unsuitable for retail sale, but are still appropriate for human consumption, for the long term sustainability of the banana industry. The optimum stage of ripeness of banana for puree making for food product development was determined through comparisons of the physical, chemical and sensory qualities. Banana pulp samples were analysed for texture, total soluble solids, starch, sugar, total ash, and potassium and magnesium contents at different ripening stages. At stage 5 ripeness, banana pulp had potassium (584 mg/100 g), magnesium (58 mg/100 g), total sugar (5.2 g/100 g) and starch (1.8 g/100 g) contents. Stage 5 ripened bananas were found to be the most suitable for puree production. Sensory acceptability results showed that the puree produced with second grade test bananas was rated significantly better compared to a commercial puree.

Fibrous Cellular Structures are Found in a Commercial Fruit Smoothie and Remain Intact during Simulated Digestion

The intactness of cell wall structures in foods has important repercussions for nutrient digestion and availability. In this study, we show the presence of intact cell wall structures in a commercial fruit smoothie (blend of banana, mango, orange and apple) and fruit puree (banana, mango), but not in fruit juices (apple or orange). Small clusters of cells were observed in fresh crushed fruit (banana, mango, and apple), the size of the cluster dependent on the type of fruit. When the smoothie was subjected to simulated gastro-intestinal digestion, cell wall structures were found abundantly even after 16 hrs of agitated incubation with digestive enzymes (protease, amylase and amyloglucosidase). Total dietary fibre (TDF) content of the smoothie was measured using the AOAC (991.43) and integrated fibre (IF) analysis methods. TDF-AOAC value was significantly lower (1.61%) than the TDF-IF (2.22%), but the ratio of insoluble to soluble dietary fibre (IDF: SDF) was consistently 1:3. Disruption of the cell wall structures in the smoothie by high shear homogenisation led to a 68% reduction in viscosity, 30% reduction in TDF content and a 10% increase in SDF. These experiments suggest that cell wall structures similar to those observed in crushed fruit are preserved during commercial smoothie manufacture and are retained during digestion. Their presence may have implications for fibre quantification and fibre functionality in the gut. We discuss the need to consider fibre structure, as well as content, when evaluating the nutritional properties of fruit and their products.

Characterizing Commercial Pureed Foods: Sensory, Nutritional, and Textural Analysis

Dysphagia (swallowing impairment) is a common consequence of stroke and degenerative diseases such as Parkinson's and Alzheimer's. Limited research is available on pureed foods, specifically the qualities of commercial products. Because research has linked pureed foods, specifically in-house pureed products, to malnutrition due to inferior sensory and nutritional qualities, commercial purees also need to be investigated. Proprietary research on sensory attributes of commercial foods is available; however direct comparisons of commercial pureed foods have never been reported. Descriptive sensory analysis as well as nutritional and texture analysis of commercially pureed prepared products was performed using a trained descriptive analysis panel. The pureed foods tested included four brands of carrots, of turkey, and two of bread. Each commercial puree was analyzed for fat (Soxhlet), protein (Dumas), carbohydrate (proximate analysis), fiber (total fiber), and sodium content (Quantab titrator strips). The purees were also texturally compared with a line spread test and a back extrusion test. Differences were found in the purees for sensory attributes as well as nutritional and textural properties. Findings suggest that implementation of standards is required to reduce variability between products, specifically regarding the textural components of the products. This would ensure all commercial products available in Canada meet standards established as being considered safe for swallowing.

Influence of the production process of strawberry industrial purees on free and glycosidically bound aroma compounds

Abstract A portion of the odourless fraction of fruits bound to sugars releases aromatic substances that represent an important source of aromatic potential. During the processing of fruits, these compounds may be affected. Thus, in this work, for the first time, glycosidic aroma precursors were studied over the course of the industrial production process of commercial strawberry puree. Free volatile compounds were also studied. The results indicated that the amounts of free and bound aromatic compounds decreased, particularly in the free fraction, by more than 50% of the total amounts. The pasteurisation stage led to the greatest loss of the precursors of key strawberry odorants. However, the seed removal step offset these losses during the processing of glycosidically bound aroma compounds. The free volatile compounds that were most strongly affected were the higher alcohols and ethyl esters. This study suggests that the amounts of glycosidic aroma precursors in the raw material significantly affect the aromatic potentials of commercial purees. Industrial relevance In producing country strawberries, every year, part of this crop is discarded due to several reasons like size, deformations or even overproduction, which cause surpluses. These strawberries of second quality are suitable for human consumption. So, these are used to obtain different products such as purees. These purees are provided to other industries that use it as an ingredient in the production of fruit-based commodities. In these products the aroma and aromatic potential which is due to the content of odourless aroma precursors are important. So, to conserve and to enhance aromatic potential are necessary to know how the industrial production process of commercial strawberry puree affects aroma precursors and volatile compounds. To the best of our knowledge, the effect of fruit processing on these odourless aroma precursors has not yet been studied. We consider that the results of this study are relevant to improve the product quality and economic benefits in the industry that develops products from strawberry.

Dynamic rheology and thermal transitions in meat-based strained baby foods

Dynamic (viscoelastic) and conventional rheology (steady flow) of three commercial meat puree based strained baby foods (chicken, lamb and beef) were evaluated in the temperature range of 5–80 °C using a controlled rate rheometer and their thermal transitions were evaluated using a standard differential scanning calorimeter (0–100 °C). All samples showed a strong viscoelastic behavior with consistently higher value of storage modulus ( G′) as compared to loss modulus ( G″) in the entire frequency ( ω) range studied (0.1–10 Hz). Both G′ and G″ values decreased with an increase in temperature at studied ω ranges between 5 and 50 °C. A change in the pattern was noticed for G′ and G″ for chicken and lamb meat was found at and above 65 °C while beef exhibited similar changes at 80 °C indicating protein denaturation related events. A power-type relationship was found satisfactory ( R 2 > 0.90) to represent dynamic rheological data (storage and loss modulus-frequency). Under steady state flow, shear-thinning behavior of baby foods was generally noticed within shear rate range between 0.1 and 100 s −1. Herschel Bulkley model represented flow data (shear stress–shear rate) adequately in the temperature range of 5–50 °C. The rheological relationships were not stable or satisfactory at and above 65 °C for both dynamic and flow rheology. Thermal transition behavior evaluated using DSC confirmed the denaturation of meat proteins in the range 65 and 80 °C, which was believed to be the primary reason for the unexpected rheological behavior in this temperature zone, expected contributed by individual or group of proteins.

Color degradation kinetics of pineapple puree during thermal processing

Improvement of color, as a quality attribute of processed pineapple puree, has been made possible by the increase in knowledge of kinetic of color change. The kinetics of color degradation of pineapple puree were investigated during heat treatment at 70–110 °C in order to cover the temperature range that used in preheat and sterilization of commercial aseptic pineapple puree. Color changes associated with heat-treated puree were monitored using Hunter colorimeter ( L, a, b, total color difference—Δ E) and Browning index ( A 420). The changes in L and b values fitted well to the first-order kinetic model while Δ E, a value, and Browning index followed the zero-order kinetic. The dependence of the rate constant on temperature was represented by an Arrhenius equation. The results suggested that Δ E and lightness, based on activation energy, were the most sensitive measures of color change at temperature range 70–90 and 95–110 °C, respectively.

Viscoelastic properties of sweet potato puree infant food

Dynamic mechanical spectroscopy and steady-shear rheological tests were carried out to evaluate viscoelastic properties of commercial sweet potato puree infant food using a controlled stress rheometer. The puree behaved like an elastic solid with G′ predominating over G″( G′ > G″). Both elastic and viscous moduli decreased with an increase in temperature while an abnormal increase in G′ was noticed at 65 °C. Steady shear viscometry, covering the shear rate range 0.1 to 100 s −1, generally indicated the presence of yield stress and good fit of data by the Herschel–Bulkley model. The complex shear viscosity ( η*) and apparent viscosity ( η) decreased with temperature between 5 and 50 °C. A modified Cox–Merz rule with a shift factor resulted in superimposition of steady and dynamic shear viscosity data. A deviation in rheological behavior at and above 65 °C was likely caused by gelatinization and possible amylase–lipid complex formation of sweet potato starch as confirmed by two distinct DSC thermal transitions peaks (57 and 94.5 °C).

Comparisons of methods for measuring yield stresses in potato puree: effect of temperature and freezing

Seven methods for determining yield stress of concentrated suspensions were applied to fresh and frozen/thawed natural and commercial purees at different temperatures, and results were compared. Since potato puree was consistent with Herschel–Bulkley flow behaviour, yield stress was more reliably determined by extrapolation of the flow curves assuming Herschel–Bulkley model than Bingham and Casson models. Methods for determining yield stress by dynamic rheological tests were tedious and are not always applicable. Given the high correlation between Herschel–Bulkley yield stress and that as determined by Bohlin option ( R 2 = 0.8735), Bohlin’s “Yield stress option” appears to be highly useful for direct measurement of this property in potato puree. Temperature influenced yield stresses more in frozen than in fresh purees, both natural and commercial. At equal temperatures, processing reduced yield stresses in natural puree but increased them in commercial puree, showing that their structures were not affected in the same way.

Rheological behaviour of fresh and frozen potato puree in steady and dynamic shear at different temperatures

Rheological behaviour of natural and commercial potato purees was studied in steady and dynamic shear conditions at sample temperatures ranging from 25–65 °C. Both types of puree were frozen-then-thawed to determine how changes occurring in their structure affected their rheological behaviour. All of the purees presented shear-thinning behaviour with yield stress. Dynamic shear data revealed weak gel-like behaviour in the purees: magnitudes of G′ were higher than those of G″, and both increased with frequency. For fresh natural puree and fresh and frozen/thawed commercial puree, the frequency dependence of G′ increased, and the frequency dependence of G″ decreased with sample temperature. Processing weakened the structure of natural puree but resulted in a coarsely aggregated structure in commercial puree. The effect of sample temperature on dynamic parameters was more significant in processed than in fresh purees. The Cox-Merz rule was not applicable to the steady and dynamic shear data on all of the purees. For fresh natural puree, the two types of data conformed to the use of shift factor on frequency, and therefore for this product it would be possible to estimate steady shear data from dynamic shear data, and vice versa. For fresh commercial puree, the relationship between steady and dynamic shear data was non-linear. In both processed purees, the linearity or otherwise of the relationship between viscosities was dependent on sample temperature.

Structural and sensory characterization of compounds contributing to the bitter off-taste of carrots (Daucus carota L.) and carrot puree.

Sequential application of solvent extraction, gel permeation chromatography, and HPLC in combination with taste dilution analyses revealed that not a sole compound but a multiplicity of bitter tastants contribute to the bitter off-taste of cold-stored carrots and commercial carrot puree, respectively. Among these bitter compounds, 3-methyl-6-methoxy-8-hydroxy-3,4-dihydroisocoumarin (6-methoxymellein), 5-hydroxy-7-methoxy-2-methylchromone (eugenin), 2,4,5-trimethoxybenzaldehyde (gazarin), (Z)-heptadeca-1,9-diene-4,6-diin-3,8-diol (falcarindiol), (Z)-heptadeca-1,9-diene-4,6-diin-3-ol (falcarinol), and (Z)-3-acetoxy-heptadeca-1,9-diene-4,6-diin-8-ol (falcarindiol 3-acetate) could be identified on the basis of MS as well as 1D- and 2D-NMR experiments. Due to the low concentrations of <0.1 mg/kg and the high taste thresholds found for eugenin and gazarin, these compounds could be unequivocally excluded as important contributors to the bitter taste of carrots. Calculation of bitter activity values as the ratio of their concentration to their bitter detection threshold clearly demonstrated that neither in fresh and stored carrots nor in commercial carrot puree did 6-methoxymellein contribute to the bitter off-taste. In contrast, the concentrations of falcarindiol in stored carrots and, even more pronounced, in carrot puree were found to be 9- and 13-fold above its low bitter detection concentration of 0.04 mmol/kg, thus demonstrating that this acetylenic diol significantly contributes to the bitter taste of the carrot products investigated.

Volatile components and aroma active compounds in aqueous essence and fresh pink guava fruit puree (Psidium guajava L.) by GC-MS and multidimensional GC/GC-O.

Characterization of the aromatic profile in commercial guava essence and fresh fruit puree by GC-MS yielded a total of 51 components quantified. Commercial essence was characterized to present a volatile profile rich in components with low molecular weight, especially alcohols, esters, and aldehydes, whereas in the fresh fruit puree terpenic hydrocarbons and 3-hydroxy-2-butanone were the most abundant components. In the olfactometric analyses totals of 43 and 48 aroma active components were detected by the panelists in commercial essence and fruit puree, respectively. New components were described for the first time as active aromatic constituents in pink guava fruit (3-penten-2-ol and 2-butenyl acetate). Principal differences between the aroma of the commercial guava essence and the fresh fruit puree could be related to acetic acid, 3-hydroxy-2-butanone, 3-methyl-1-butanol, 2,3-butanediol, 3-methylbutanoic acid, (Z)-3-hexen-1-ol, 6-methyl-5-hepten-2-one, limonene, octanol, ethyl octanoate, 3-phenylpropanol, cinnamyl alcohol, alpha-copaene, and an unknown component. (E)-2-Hexenal seems to be more significant to the aroma of the commercial essence than of the fresh fruit puree.

IMPERFECT SQUEEZING FLOW VISCOSIMETRY OF SELECTED TOMATO PRODUCTS1

ABSTRACTThe rheological properties of different brands of commercial tomato paste, sauce, puree and ketchup were estimated by imperfect squeezing flow viscosimetry using a wide plate and a shallow container. The tests were performed with polished and grooved surfaces. In both, slip was prominent to such an extent that the equations for lubricated squeezing flow had to be used for the calculation of rheological parameters. Despite its crudeness, the procedure was sensitive enough to consistently monitor rheological differences between commercial products of different brands in terms of the apparent stress at a given specimen height, the consistency, K, and flow index, n, of the pseudoplastic liquid constitutive equation, and the apparent biaxial elongational viscosity, μb and its strain rate dependency. In tomato paste, the flow behavior index was approximately the same in all the brands (n ∼ 0.5), and the values of K and μb had a linear relationship. Residual forces after relaxation provided an additional textural measure related to the yield stress. Differences between products of different brands could be consistently monitored regardless of whether the test was performed at a fixed specimen height or a preset initial force.

Physical and Functional Properties of Mechanically Deboned Poultry Meat as Used in the Manufacture of Frankfurters

Frankfurters were made from laboratory prepared mechanically deboned poultry meat (MDPM) using backs and necks. They were compared with frankfurters made from commercially made puree (mechanically deboned meat) and hand deboned carcass meat. Variables studied were (1) the effect of grind and screen sizes used in the production of the MDPM; (2) the effect of the percent of added skin in the formula; and (3) the effect of selected additives. Parameters used for evaluation included organoleptic scores, emulsion stability and shear press values.The smaller the screen size, the more tender, better flavored and more acceptable were the end products. Hand deboned carcass produced the firmest frankfurter. Flavor and acceptability of frankfurters from both hand deboned carcasses and commercial puree were not significantly different as compared to the product made with MDPM from the smallest screen (0.05 cm.).Increasing the skin added to the formula increased the fat content, increased organoleptic tenderness and viscosity and decreased emulsion stability.The addition of 3% sodium caseinate, 3% acid whey or 0.5% Kena had very little effect on the organoleptic qualities of the frankfurters. Kena markedly decreased emulsion viscosity, whereas, sodium caseinate increased it.