Quality attributes of processed tomato products: A review

Potential Use of Tomato Peel, a Rich Source of Lycopene, for Cancer Treatment

Tomatoes are well known for their impressive nutritional value among vegetables. However, the industrial processing of tomatoes generates a significant amount of waste. Specifically, 10% to 18% of the raw materials used in tomato processing become waste. This waste can seriously affect ecosystems, such as freshwater bodies, wetlands, rivers, and other natural environments, if not properly managed. Interestingly, tomato waste, specifically the skin, contains lycopene, a potent antioxidant and antimutagenic that offers a range of health benefits. This makes it a valuable ingredient in industries such as food and cosmetics. In addition, researchers are exploring the potential of lycopene in the treatment of various types of cancer. This systematic review, guided by the PRISMA 2020 methodology, examined studies exploring the possibility of tomato peel as a source of lycopene and carotenoids for cancer treatment. The findings suggest that tomato peel extracts exhibit promising anticancer properties, underscoring the need for further investigation of possible therapeutic applications. The compiled literature reveals significant potential for using tomato peel to create new cancer treatments, which could potentially revolutionize the field of oncology. This underscores the importance of continued research and exploration, emphasizing the urgency and importance of the scientific community's contribution to this promising area of study.

Nano and chelated iron fertilization influences marketable yield, phytochemical properties, and antioxidant capacity of tomatoes

Iron (Fe) is one of the limiting micronutrients essential for crop productivity. The goal of our study was to evaluate the effects of different sources and rates of Fe fertilization on the marketable yield, physical and chemical properties, and phytochemical quality of fresh market tomatoes (Solanum Lycopersicum L., cv. Sunbrite). A factorial experiment under a drip-irrigated plasticulture system was conducted in a completely randomized design with two sources of Fe (nano vs. chelated) and four rates of application (0, 10, 20, and 40 mg/L) with four replications. Results indicated that relative chlorophyll concentration in the leaf (SPAD index) increased significantly (by 24 to 27%) with 10 and 20 mg/L of both nano- and chelated Fe fertilization compared to the control. Increasing Fe fertilization decreased the leaf SPAD readings. The total fruit yield of tomato was 1.6 to 1.8 times higher under the chelated- and nano Fe fertilization and the increase in yield was significantly higher under the chelated Fe fertilization, when compared to the control. In contrast, the tomato harvest index was highest under 10 and 20 mg/L of nano Fe than under other Fe treatments. While the chelated Fe fertilized tomatoes had significantly higher concentrations of vitamin C (34%), ß-carotene (6%), total carotene (25%), flavonoid (17%), and polyphenol (66%), the nano Fe, in contrast, increased ß-carotene, total carotene, and polyphenol concentrations by 25, 33, 51, and 7%, respectively, compared to the control. The 20 mg/L chelated Fe significantly increased the vitamin C, total carotene, flavonoid, polyphenol concentration, and antioxidant capacity more than any other Fe treatments. Based on the principal components analyses, vitamin C, lycopene, and anthocyanin were identified as the core indicators of the tomato nutrition quality index (NQIndex). The NQIndex ranged from 47 to 54, falling within the medium level of nutritional quality (40 to <70). In conclusion, the chelated Fe, when applied at 20 mg/L, was the most appropriate rate based on highly correlated connectivity for the phytochemicals syntheses associated with the improved tomato antioxidant capacity.

β-Cyclocitral-Mediated Metabolic Changes Optimize Growth and Defense Responses in Solanum lycopersicum L

β-cyclocitral (βCC) is one of the significant oxidative products of β-carotene. It primes plants for multiple stress acclimation without compromising plant growth. Metabolic reorganization is necessary to maintain a balance between growth and defense. However, the βCC-mediated changes in a plant’s metabolic network are unknown. Here, we demonstrate how βCC-induced metabolic changes enable Solanum lycopersicum L. (tomato) plants to promote defense and maintain growth under stress. An analysis of early (0–240 min) and late (72 h) changes in the tomato metabolome after βCC-treatment using liquid chromatography and tandem mass spectrometry identified 57 compounds. A principal coordinate analysis suggested that βCC treatment significantly changes the metabolite profile. A variable importance in projection (VIP) analysis revealed 16 and 19 discriminant metabolites from early and late samples, respectively (VIP ≥ 1.0). Upregulated metabolites were mainly amino acids and phytophenols. Pathway enrichment analysis showed that βCC treatment influenced amino acid metabolism at early and later times; however, phenylpropanoid and isoquinoline biosynthesis were influenced only at the later time. A 66.6% similarity in the upregulated metabolites of βCC- and simulated-herbivory-treated plants confirmed βCC’s role against herbivores. We conclude that βCC steers a temporal separation in amino acids and defense metabolite accumulation that optimizes resource allocation to growth and defense.

Use of Ulva reticulata as a growth supplement for tomato (Solanum lycopersicum)

Mass proliferation and accumulation of the green macroalga Ulva reticulata are problems in coastal areas and affect other ecosystems, such as those involving seagrasses. In the absence of any intervention, the decomposition of these macroalgae over time can disrupt the balance of recipient ecosystems. Attention has been given to the potential use of U. reticulata as a supplier of nutrients for crop species such as tomatoes as a possible solution to the buildup of this unusable seaweed species, which is usually left to decompose in affected seagrass ecosystems; this is the case in the Merambong seagrass meadow in the Sungai Pulai estuary in Gelang Patah, southwestern Johor, Malaysia. We analyzed the macro- and micronutrient contents in U. reticulata to determine nutrient availability. We also performed greenhouse studies to test the effects of crude extracts from dried U. reticulata-Extract “A” and fresh U. reticulata-Extract “B” on plant growth, total yield, and quality vine-ripened fruits. Compared to other seaweed extracts used as plant growth promoters, U. reticulata extracts have higher nitrogen (N), manganese (Mn), zinc (Zn), and iron (Fe) contents. The application of 30% Extracts “A” and “B” and 50% Extracts “A” and “B” significantly affected tomato plant height. However, extract concentrations that promoted plant height and hastened flowering and fruiting did not increase total fruit yields. Both treatments that positively affected tomato plant height and hastened flowering and fruiting resulted in increased contents of total soluble solids (TSS), beta-carotene, lycopene, ascorbic acid and total titratable acidity (TTA) in the vine-ripened fruits. Agronomically, the application of 5% Extracts “A” and “B”, 10%-20% Extracts “A” and “B”, and 50% Extract “A” doubled the total yield compared to those of the control, and 40% Extract “A” resulted in the highest total fruit yield. In general, tomato plants responded well to Extract “A” than Extract “B” and presented good total fruit yield and quality.

β-Cyclocitral, a Master Regulator of Multiple Stress-Responsive Genes in Solanum lycopersicum L. Plants

β-cyclocitral (βCC), a major apocarotenoid of β-carotene, enhances plants' defense against environmental stresses. However, the knowledge of βCC's involvement in the complex stress-signaling network is limited. Here we demonstrate how βCC reprograms the transcriptional responses that enable Solanum lycopersicum L. (tomato) plants to endure a plethora of environmental stresses. Comparative transcriptome analysis of control and βCC-treated tomato plants was done by generating RNA sequences in the BGISEQ-500 platform. The trimmed sequences were mapped on the tomato reference genome that identifies 211 protein-coding differentially expressed genes. Gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis and their enrichment uncovered that only upregulated genes are attributed to the stress response. Moreover, 80% of the upregulated genes are functionally related to abiotic and biotic stresses. Co-functional analysis of stress-responsive genes revealed a network of 18 genes that code for heat shock proteins, transcription factors (TFs), and calcium-binding proteins. The upregulation of jasmonic acid (JA)-dependent TFs (MYC2, MYB44, ERFs) but not the JA biosynthetic genes is surprising. However, the upregulation of DREB3, an abscisic acid (ABA)-independent TF, validates the unaltered expression of ABA biosynthetic genes. We conclude that βCC treatment upregulates multiple stress-responsive genes without eliciting JA and ABA biosynthesis.

High Pressure Processing vs. Thermal Pasteurization of Whole Concord Grape Puree: Effect on Nutritional Value, Quality Parameters and Refrigerated Shelf Life

High-pressure processing (HPP) is utilized for food preservation as it can ensure product safety at low temperatures, meeting consumers’ demand for fresh-like and minimally processed products. The purpose of this study was to determine the effects of HPP (600 MPa, 3 min, 5 °C) and pasteurization by heat treatment (HT, 63 °C, 3 min) on the production of a novel whole Concord grape puree product (with skin and seeds, no waste), and the shelf-life of the puree under refrigerated storage (4 °C). Microbial load, physicochemical properties, phenolic content and antioxidant activity, composition and sensorial attributes of puree samples were evaluated. HPP- and HT-treated purees were microbiologically stable for at least 4 months under refrigeration, with less microbial growth and longer shelf life for HPP samples. HPP and HT samples had similar levels of phenolic contents and antioxidant activities throughout the 4-month refrigerated storage period, even though HPP retained >75% PPO and POD enzyme activities while those of HT were less than 25%. Inclusion of seeds in the puree product significantly increased the fiber, protein, total fatty acid, and linoleic acid contents. Sensory results showed that HPP-treated puree retained more fresh-like grape attributes, had better consistency, and showed significantly higher ratings in consumer overall liking, product ranking, and purchase intent than the HT puree (p < 0.05).

Are Processed Tomato Products as Nutritious as Fresh Tomatoes? Scoping Review on the Effects of Industrial Processing on Nutrients and Bioactive Compounds in Tomatoes

Tomatoes are the second most consumed vegetable in the United States. In 2017, American people consumed 9.2 kg of tomatoes from a fresh market and 33.2 kg of processed tomato products per capita. One commonly asked question by consumers and the nutrition community is "Are processed tomato products as nutritious as fresh tomatoes?" This review addresses this question by summarizing the current understandings on the effects of industrial processing on the nutrients and bioactive compounds of tomatoes. Twelve original research papers were found to study the effects of different industrial processing methods on the nutrients and/or bioactive compounds in tomato products. The data suggested that different processing methods had different effects on different compounds in tomatoes. However, currently available data are still limited, and the existing data are often inconsistent. The USDA National Nutrient Database for Standard Reference Legacy was utilized to estimate nutrient contents from raw tomatoes and processed tomato products. In addition, several other important factors specifically related to the industrial processing of tomatoes were also discussed. To conclude, there is no simple "yes" or "no" answer to the question "Are processed tomato products as nutritious as fresh tomatoes?" Many factors must be considered when comparing the nutritious value between fresh tomatoes and processed tomato products. At this point, we do not have sufficient data to fully understand all of the factors and their impacts.

Formulation engineering of food systems for 3D-printing applications - A review

The efficient development of extrusion-based 3D-printing requires flexibility in both formulation- and process design. This task requires a fundamental understanding of the influence of material rheological properties on the extrusion process. Within this review, a qualitative toolbox for food extrusion is presented which provides guidelines for the formulation and engineering of extrusion processes in general and 3D-printing in particular. The toolbox is based on current knowledge of highly viscous food systems and the influence of individual components on the overall rheology. It includes the efficiency of particle packing, microstructure and the influence of shear rate, as well as the formation of self-supporting structures by gelation of the liquid phase and crowding of particles. Physical laws and semi-empirical equations are discussed to describe the rheology and relate relevant theory to the extrusion process. Practical information is presented, including examples of extrusion and 3D-printing of food and non-food systems. The qualitative extrusion toolbox provides a general framework for the emerging field of extrusion-based 3D-printing of food products. It can be used to identify which specific material and process parameters can be changed and how they may be altered to optimize the 3D-printing process. The general framework will assist researchers, as well as industry.

Evaluation of the basic saccharides content in tomatoes

Saccharides are the basic dry matter components of all fruits and vegetables. The dominant tomatoes saccharides are fructose and glucose, minor ones are sucrose but also arabinose, xylose, and galactose. The objective of this paper is to analyze carbohydrates such as glucose, fructose and sucrose in the selected tomatoes varieties intended for the direct consumption and industrial processing. We used 14 varieties and 3 newly selected tomatoes varieties. The glucose content in the studied varieties was in the range of 4.87 – 15.9 g.kg-1, the fructose content was 11.1 – 22.27 g.kg-1 and sucrose content was 0.07 – 1.73 g.kg-1. The highest fructose and sucrose content was detected in the Tomanova variety, the highest sucrose content was found out in the Bovita variety. When comparing the glucose content it was found out that the higher content on average was achieved in the varieties intended for the industrial processing (10.10 g.kg-1) than in the varieties for the direct consumption (7.96 g.kg-1). The varieties intended for industrial processing were generally characterized by higher glucose and fructose content than the varieties intended for the direct consumption. When comparing the fructose content, we found a higher average content in the varieties intended for industrial processing (15.70 g.kg-1) than in the varieties for the direct consumption (14.40 g.kg-1). In most of the studied varieties sucrose was present in low content (<1.0 g.kg-1), only in the Tomanova variety sucrose content represented more than 1 g.kg-1.

Effects of air-impingement jet drying on drying kinetics and quality retention of tomato slices

The purpose was to explore the drying kinetics, the moisture effective diffusivities, color, total polyphenols, lycopene and antioxidant activities of dried tomato slices by air-impingement jet drying (AIJD). The results showed that high temperature increased the drying rate, and Modified Page model accurately predicted the AIJD characteristics of tomato slices. AIJD is better than hot air drying in shortening drying time, enhancing drying rate and decreasing the loss of total polyphenols, lycopene and antioxidant capacity of tomato slices. Tomato slices dried by AIJD also showed higher lightness and redness. Lycopene content and antioxidant activity of tomato slices dried by AIJD were increased by higher drying temperature. Based on experimental data, AIJD at 80 °C can be used in tomato drying process due to the advantages in drying efficiency and content of bioactive compounds. This study will provide helpful information for the production of high quality of dried tomato products.

Detection and Quantification of Tomato Paste Adulteration Using Conventional and Rapid Analytical Methods

Tomato, and its concentrate are important food ingredients with outstanding gastronomic and industrial importance due to their unique organoleptic, dietary, and compositional properties. Various forms of food adulteration are often suspected in the different tomato-based products causing major economic and sometimes even health problems for the farmers, food industry and consumers. Near infrared (NIR) spectroscopy and electronic tongue (e-tongue) have been lauded as advanced, high sensitivity techniques for quality control. The aim of the present research was to detect and predict relatively low concentration of adulterants, such as paprika seed and corn starch (0.5, 1, 2, 5, 10%), sucrose and salt (0.5, 1, 2, 5%), in tomato paste using conventional (soluble solid content, consistency) and advanced analytical techniques (NIR spectroscopy, e-tongue). The results obtained with the conventional methods were analyzed with univariate statistics (ANOVA), while the data obtained with advanced analytical methods were analyzed with multivariate methods (Principal component analysis (PCA), linear discriminant analysis (LDA), partial least squares regression (PLSR). The conventional methods were only able to detect adulteration at higher concentrations (5–10%). For NIRS and e-tongue, good accuracies were obtained, even in identifying minimal adulterant concentrations (0.5%). Comparatively, NIR spectroscopy proved to be easier to implement and more accurate during our evaluations, when the adulterant contents were estimated with R² above 0.96 and root mean square error (RMSE) below 1%.

Non-Destructive Quality Assessment of Tomato Paste by Using Portable Mid-Infrared Spectroscopy and Multivariate Analysis

This research aims to provide simultaneous predictions of tomato paste's multiple quality traits without any sample preparation by using a field-deployable portable infrared spectrometer. A total of 1843 tomato paste samples were supplied by four different leading tomato processors in California, USA, over the tomato seasons of 2015, 2016, 2017, and 2019. The reference levels of quality traits including, natural tomato soluble solids (NTSS), pH, Bostwick consistency, titratable acidity (TA), serum viscosity, lycopene, glucose, fructose, ascorbic acid, and citric acid were determined by official methods. A portable FT-IR spectrometer with a triple-reflection diamond ATR sampling system was used to directly collect mid-infrared spectra. The calibration and external validation models were developed by using partial least square regression (PLSR). The evaluation of models was conducted on a randomly selected external validation set. A high correlation (RCV = 0.85-0.99) between the reference values and FT-IR predicted values was observed from PLSR models. The standard errors of prediction were low (SEP = 0.04-35.11), and good predictive performances (RPD = 1.8-7.3) were achieved. Proposed FT-IR technology can be ideal for routine in-plant assessment of the tomato paste quality that would provide the tomato processors with accurate results in shorter time and lower cost.

Extraction of Carotenoids from Tomato Pomace via Water-Induced Hydrocolloidal Complexation

Agro-industrial waste is a largely untapped natural resource of bioactive compounds including carotenoids and pectin. However, conventional solvent extraction involves the excessive use of organic solvents, costly equipment, and tedious operation. These limitations of conventional extraction methods could be prospectively overcome by the carotenoid-pectin hydrocolloidal complexation. The complexation of lycopene and pectin was efficiently promoted in an aqueous environment, resulting in the colloidal complexes that can be subsequently recovered by sedimentation or centrifugation. In this study, the potential of carotenoid-pectin complexation on tomato pomace containing carotenoids and pectin was evaluated. Tomato pomace is a rich source of lycopene, β-carotene as well as pectin, making it suitable as the raw material for the carotenoid extraction. The extraction of carotenoid and pectin from tomato pomace was optimized using response surface methodology. The maximum recovery was 9.43 mg carotenoid fractions/100 g tomato pomace, while the purity of carotenoid-rich fractions was 92%. The antioxidant capacity of carotenoids extracted from the complexation method was found to be higher than that from the solvent extraction method. Moreover, extraction yield and antioxidant capacity of carotenoid obtained from the carotenoid-pectin complexation were comparable to that from solvent extraction. The carotenoid-pectin complexation is a promising green approach to valorize agro by-products for the extraction of valuable carotenoids.

Transcriptional changes during tomato ripening and influence of brackish water irrigation on fruit transcriptome and sugar content

Efficient management and utilization of brackish water irrigation help to minimize yield losses and promote fruit quality and sugar content in tomato fruit. However, the functional genes involved in sugar metabolic pathways and potential molecular pathways responsive to brackish water irrigation remain unknown. To this end, physiological responses and comparative transcriptional profiling was used to analyze the tomato fruit during the white-ripe period (CK1) and mature period (CK2) in plants grown under four water management strategies (rotating irrigation with brackish and fresh water during fruit development, T1; fresh water irrigation, T2; mixed brackish and fresh water irrigation, T3; mixed water and fresh water irrigation in sequence, T4). Comparative analysis revealed that during fruit development (CK2 cv CK1) differentially expressed genes (DEGs) involved in photosynthetic pathways and sucrose-starch metabolism were downregulated. However, two DEGs encoding putative beta-fructofuranosidases were significantly upregulated at the mature stage, which promoted the accumulation of glucose and fructose in CK2. Comparing four types of management strategies, rotating irrigation with brackish water and fresh water (T1) led to reprograming of global gene expression. Moreover, the upregulated DEGs in T1 were significantly enriched for signaling, hormone metabolism, and stress tolerance, suggesting the coordination of both stresses signaling as well as the plant hormone. These results provide a valuable reference for rational use of brackish water in the production of high-quality tomato in arid and semi-arid regions.

Morphological and Chemical Profile of Three Tomato (Solanum lycopersicum L.) Landraces of A Semi-Arid Mediterranean Environment

Puglia (Southern Italy), particularly rich in tomato agro-biodiversity, can be considered a typical region of the semi-arid Mediterranean environments. In this study, three local varieties of tomato (Manduria, Giallo di Crispiano and Regina) were characterized by using morphological descriptors according to international standards. Chemical (isoprenoids, ascorbic acid, total phenols, sugars and mineral content) and agronomic assessment were carried out to highlight the specific traits of these local varieties well adapted to a semi-arid environment. Data of morphological traits according to the “International Union for the Protection of New Varieties of Plants” (UPOV) guideline evidenced a clear distinctness among all three landraces, especially as regards fruits. Results also highlighted that a great part of variation in chemical traits was almost exclusively due to genotypes, while in a few cases observed differences resulted from the interaction between genotype and harvest time. The results of the present study may represent the first step toward the recognition of “conservation variety” status for Regina, Giallo di Crispiano and Manduria tomato landraces. At the same time, both quality traits and agronomic performance of these tomato genotypes suggest the possibility of their cultivation in other semi-arid environments also considering their quality traits, in view of a sustainable production.

Determination of developmental and ripening stages of whole tomato fruit using portable infrared spectroscopy and Chemometrics

BACKGROUND

Development and ripening of tomato (Solanum lycopersicum) fruit are important processes for the study of crop biology related to industrial horticulture. Versatile uses of tomato fruit lead to its harvest at various points of development from early maturity through to red ripe, traditionally indicated by parameters such as size, weight, colour, and internal composition, according to defined visual 'grading' schemes. Visual grading schemes however are subjective and thus objective classification of tomato fruit development and ripening are needed for 'high-tech' horticulture. To characterize the development and ripening processes in whole tomato fruit (cv. Moneymaker), a biospectroscopy approach is employed using compact portable ATR-FTIR spectroscopy coupled with chemometrics.

RESULTS

The developmental and ripening processes showed unique spectral profiles, which were acquired from the cuticle-cell wall complex of tomato fruit epidermis in vivo. Various components of the cuticle including Cutin, waxes, and phenolic compounds, among others, as well as from the underlying cell wall such as celluloses, pectin and lignin like compounds among others. Epidermal surface structures including cuticle and cell wall were significantly altered during the developmental process from immature green to mature green, as well as during the ripening process. Changes in the spectral fingerprint region (1800-900 cm^- 1) were sufficient to identify nine developmental and six ripening stages with high accuracy using support vector machine (SVM) chemometrics.

CONCLUSIONS

The non-destructive spectroscopic approach may therefore be especially useful for investigating in vivo biochemical changes occurring in fruit epidermis related to grades of tomato during development and ripening, for autonomous food production/supply chain applications.

Shelf Life Extension of Tomato Paste Through Organoleptically Acceptable Concentration of Betel Leaf Essential Oil Under Accelerated Storage Environment

This study was attempted with two objectives: (1) to find an acceptable concentration of betel leaf essential oil (BLEO) based on sensory evaluation that can be employed in tomato paste; (2) to evaluate the effect of the acceptable concentration of BLEO in the paste during accelerated storage under 89 ± 1.2% RH at 39 ± 1 °C. Linguistic data obtained from sensory evaluation of tomato paste treated with 4 different concentrations of BLEO were analyzed using fuzzy logic approach. The organoleptically acceptable concentration was determined to be 0.25 mg/g of BLEO in tomato paste. The effect of the selected concentration of BLEO on different physicochemical and microbial attributes of tomato paste during accelerated storage was studied. Untreated tomato paste was found to have 12% less total antioxidant capacity than treated paste at the end of storage. Based on a^* /b^* value in CIELAB color space, the BLEO treated paste efficiently extended the shelf life by 14 days with respect to untreated paste samples under accelerated storage conditions. BLEO comes with a tag contributing to green consumerism, and its application as food preservative is no less than a value addition to the product.

PRACTICAL APPLICATIONS

Essential oil is considered to have promising potential as an alternative food preservative, and its use is practically possible if they could overcome the sensory barrier, while retaining the preservative potency. The importance of identifying the sensory attributes for commercial success of essential oil treated food product was considered in this study. It contributes to the potency of organoleptically acceptable concentration of BLEO in shelf life extension of tomato paste under accelerated storage conditions. At industrial level, the estimated shelf life of treated tomato paste can be increased by incorporating more hurdles alongside BLEO.

The quality of ketchups from the Czech Republic's market in terms of their physico-chemical properties

Ketchup is a tomato-based condiment with a tang contributed by vinegar, sugar, salt and spices. Physical and chemical quality requirements for ketchup are regulated in the Czech Republic by Decree No. 157/2003 as amended. The main monitored parameters determining the quality of ketchups are total tomato content, total soluble solids, total organic acids and total salt content. In this work the following parameters were monitored in a total of eight ketchups from the commercial markets in the Czech Republic: pH, total solids, total soluble solids, citric acid content, acetic acid content, lycopene content, fructose, glucose and sucrose content and content of Ca, K, Mg and Na. In addition to chemical analyses, rheological measurements were performed and dynamic viscosity and yield stress were determined. The results obtained were statistically processed and the hypothesis i) whether the sales price of ketchups is related to the quality of ketchups expressed in chemical composition and ii) whether the chemical composition affects the rheological properties of ketchups has been verified. The Pearson correlation matrix showed very good correlation between the total solids and tomato content in the ketchup (R = 0.8464) as well as between the total soluble solids and tomato content in the ketchup (R = 0.8583). Another significant correlation was found between total soluble solids and total saccharides content in ketchup (R = 0.7309) as well as between potassium content and and tomato content in the ketchup (R = 0.8864). The chemical composition of ketchups did not significantly affect the dynamic viscosity of ketchups, however strong correlation between tomato content in ketchup and between yield stresses was found (R = 0.8436). No correlation was found between the ketchup price and chemical composition of ketchup, however cheaper ketchups contained more salt.

The Choice of Canned Whole Peeled Tomatoes is Driven by Different Key Quality Attributes Perceived by Consumers Having Different Familiarity with the Product

Canned whole peeled tomatoes are a premium tomato product; however, no information is available about the key intrinsic and extrinsic quality attributes perceived by consumers when buying this product. This research considered consumers differing in the level of familiarity with peeled tomatoes, that is, knowledge, frequency of consumption, and availability of this product, on 3 markets: Chile (low), The Netherlands (medium), and Italy (high). The perceptions and preferences of each group were studied using first focus groups and subsequently conjoint analysis in order to identify the key quality attributes leading their preferences for this product. Focus groups identified 7 intrinsic attributes (color, packing medium, tomato consistency, acidity level, sweetness level, extra ingredients, and intensity of product taste), and 5 extrinsic attributes (packaging material, product type, country of origin, brand, and label design). Significant variations according to the familiarity were found. The conjoint analyses showed that color of tomatoes was the most important intrinsic quality attribute for all groups, while packaging material was the most important extrinsic quality attribute for Chileans and Dutch, being a glass container or a can with easy open the preferred packaging for respective groups. In contrast, country of origin was the most important parameter for Italians. We concluded that intrinsic and extrinsic attributes were strongly influenced by the degree of familiarity with canned whole peeled tomatoes.

Influence of Tomato Paste Processing on the Linear Viscoelasticity of Tomato Ketchup

Tomato paste is used as an ingredient for the manufacture of tomato ketchup. This paper deals with the influence that some tomato paste processing variables (finisher screen opening and breaking temperature) and tomato variety exert on the linear viscoelastic properties of tomato ketchup. Two tomato varieties (H-282 and H-282F) were used. H-282 is a commercial variety whilst H-282F is a variety with a lower content in polygalacturonase (PG). Dynamic viscoelastic tests and particle size distribution measurements were carried out. Viscoelastic properties of tomato ketchup were mainly related to their mean volume diameter, tomato paste water-insoluble solids content (that depended on the tomato paste processing) and tomato variety.

Dextran synthesized by Leuconostoc mesenteroides BD1710 in tomato juice supplemented with sucrose

The characteristics of the growth of Leuconostoc mesenteroides BD1710 and the synthesis of dextran in tomato juice supplemented with 15% sucrose were assayed. L. mesenteroides BD1710 could synthesize approximately 32 g L(-1) dextran in the tomato-juice-sucrose medium when cultured at 28 °C for 48 h, which was on the same level as the dextran yield in a chemically defined medium. The viscosity of the cultured tomato-juice-sucrose medium with various dextran contents was also measured. The results of the monosaccharide composition, molecular-weight distribution, Fourier transform infrared spectra (FTIR) and nuclear magnetic resonance spectra (NMR) showed that the polysaccharide synthesized by L. mesenteroides BD1710 in the tomato-juice-sucrose medium was dextran with a peak molecular weight of 6.35 × 10(5)Da, a linear backbone composed of consecutive α-(1 → 6)-linked d-glucopyranosyl units and approximately 6% α-(1 → 3) branches.

Physiochemical and phytochemical properties of wax apple (Syzygium samarangense [Blume] Merrill & L. M. Perry var. Jambu Madu) as affected by growth regulator application

This study represents the first paper of the effects of growth regulators on the physiochemical and phytochemical properties of the wax apple fruit, a widely cultivated fruit tree in southeast Asia. Net photosynthesis, sucrose phosphate synthase (SPS) activity, peel color, fruit firmness, juice content, pH value, total soluble solids (TSSs), and the sugar acid ratio were all significantly increased in growth regulators (PGRs) treated fruits. The application of gibberellin (GA(3)), naphthalene acetic acid (NAA), and 2,4-dichlorophenoxy acetic acid (2,4-D) significantly reduced titratable acidity and increased total sugar and carbohydrate content compared to the control. The 50 mg/L GA₃, 10 mg/L NAA, and 5 mg/L 2,4-D treatments produced the greatest increases in phenol and flavonoid content; vitamin C content was also higher for these treatments. PGR treatment significantly affected chlorophyll, anthocyanin, and carotene content and produced higher phenylalanine ammonia lyase (PAL) and antioxidant activity levels. There was a positive correlation between peel color and TSS and antioxidant activity and both phenol and flavonoid content and PAL activity and anthocyanin formation. A taste panel assessment was also performed, and the highest scores were given to fruits that had been treated with GA₃ or auxin. The study showed that application of 50 mg/L GA₃, 10 mg/L NAA, and 5 mg/L 2,4-D once a week from bud development to fruit maturation increased the physiochemical and phytochemical properties of wax apple fruits.

Applications of ultrasound in food technology: Processing, preservation and extraction

Ultrasound is well known to have a significant effect on the rate of various processes in the food industry. Using ultrasound, full reproducible food processes can now be completed in seconds or minutes with high reproducibility, reducing the processing cost, simplifying manipulation and work-up, giving higher purity of the final product, eliminating post-treatment of waste water and consuming only a fraction of the time and energy normally needed for conventional processes. Several processes such as freezing, cutting, drying, tempering, bleaching, sterilization, and extraction have been applied efficiently in the food industry. The advantages of using ultrasound for food processing, includes: more effective mixing and micro-mixing, faster energy and mass transfer, reduced thermal and concentration gradients, reduced temperature, selective extraction, reduced equipment size, faster response to process extraction control, faster start-up, increased production, and elimination of process steps. Food processes performed under the action of ultrasound are believed to be affected in part by cavitation phenomena and mass transfer enhancement. This review presents a complete picture of current knowledge on application of ultrasound in food technology including processing, preservation and extraction. It provides the necessary theoretical background and some details about ultrasound the technology, the technique, and safety precautions. We will also discuss some of the factors which make the combination of food processing and ultrasound one of the most promising research areas in the field of modern food engineering.