Effect of Equivalent Thermal Treatments on the Color and the Antioxidant Activity of Tomato Puree

Effects of ultra-high pressure, thermal pasteurization, and ultra-high temperature sterilization on color and nutritional components of freshly-squeezed lettuce juice

The aim of this study was to evaluate the effects of ultra-high pressure (UHP, 600 MPa/2 min), thermal pasteurization (TP, 95 °C/1 min) and ultra-high temperature (UHT, 115 °C/5 s) sterilization on the color, sensory evaluation, microorganisms, physicochemical characteristics and nutritional components of freshly-squeezed lettuce juice (FLJ). Results showed that three sterilization methods demonstrated desirable inactivation effects on total aerobic bacteria, yeast and mold, and there were no significant changes in the main nutritional components, including ash, protein, carbohydrate and total dietary fiber. However, UHT and TP significantly affected the color of FLJ from bright green to light brown and made chlorophyll, β-carotene and vitamins (VE, VC, VK1, VB6, VB12, and folic acid) contents markedly decreased. By contrast, UHP maintained the original color, fresh-like sensory qualities, vitamins, and carotene of FLJ to the greatest extent. Our results provide a promising application of UHP in the large-scale processing of FLJ.

Ranking based formula optimization, quality investigation, and real-time shelf-life prediction of ready-to-eat ricebean (Vigna umbellata) curry

Ricebean (Vigna umbellata) is an underutilized bean of South and South-East Asia, was exploited to formulate the ready-to-eat curry by using thermal processing technology. Eleven types of RTE ricebean curries (RBCs) namely RBC1, RBC2, RBC3, RBC4, RBC5, RBC6, RBC7, RBC8, RBC9, RBC10, RBC11 were developed by varying the proportion of tomato paste, onion paste, and coriander powder after thermal processing at 121 °C (15 psi) for 20 min. Out of these, the best quality curry was selected based on the total product ranking score (TPRS) which was calculated from the curry quality parameters such as consistency, pH, loss due to sorption onto the inner surface of the retort pouch (LOSS), and sensory (overall acceptability-OAA). Among the curries, RBC2 secured the highest value of TPRS, named it as RTE-RBC and was used to study the physico-chemical, textural, nutritional, microbial, sensory parameters and storage stability. The DPPH-antioxidant activity of RTE-RBC was 2.47 µM BHA/g which was due to the presence of bioactive phytochemicals such as polyphenol, flavonoids, lycopene, gingerol, ɣ-Oryzanol, and capsaicin. It was observed that the in-vitro protein/carbohydrate digestibility, in-vitro calcium bioavailability and real-time shelf-life (predicted) of RTE-RBC were 85%, 54%, and one year, respectively.

Red Tomato Products as an Alternative to Reduce Synthetic Dyes in the Food Industry: A Review

Most dyes used in the food industry are synthetic and can be a health hazard. Red tomato may serve as a natural alternative dye to replace synthetic colorants. This study aimed to review the literature on the addition of red tomato products (powder tomato, paste, freeze-dried, tomato peel powder, tomato pomace) to reduce the usage of synthetic dyes in the food industry. Red tomato products have been used as coloring in pasta, bologna, sausages, cookies, crackers, macaroons, hamburgers, breads, muffins, cheeses, and nuggets. The trans-cis isomerization of lycopene by oxidative processes directly affects the color of the pigment. The lycopene contained in tomato has antioxidant activity and could reduce or eliminate other oxidants and/or synthetic preservatives in food. Moreover, tomatoes in foods have high sensory scores, nutritional appeal, and marketing potential. However, its use as a food colorant has been not extensively explored. Therefore, further studies are still required, especially on the stability of carotenoids in tomatoes used in processed foods.

Preliminary Investigation on the Physicochemical and Functional Properties of Commercial Salmorejo Found in Spanish Supermarkets

Salmorejo is a traditional Spanish food made of raw tomatoes, bread, garlic, and virgin olive oil. The food industry aims to satisfy consumer demand for ready-to-eat salmorejo while trying to maintain characteristics of the homemade product. In this work, we have assessed physical-chemical and color parameters, radical scavenging activity, and total polyphenol, lycopene, and β-carotene contents of raw and pasteurized commercial salmorejo, as well as homemade (raw) salmorejo samples. Our results showed that heat treatment had a significant influence on color parameters of salmorejo, with pasteurized samples being less red and exhibiting an increase in the degree of browning. Pasteurized samples also showed the highest radical scavenging activity when expressing the results per dry weight. However, when water content was considered, radical scavenging activity was superior in homemade samples when analyzing non-polar molecules extracted with acetone. Results were similar for polyphenol content. It was also observed that heat treatment affected lycopene but not β-carotene content. When acquiring commercial salmorejo at the supermarket, consumers have the option to choose between already prepared pasteurized or raw salmorejo. According to the results obtained in this work, physicochemical and functional properties of commercial raw salmorejo were comparable to a larger extent than pasteurized salmorejo compared to those exhibited by homemade salmorejo samples.

LC-MS/MS for simultaneous detection and quantification of Amadori compounds in tomato products and dry foods and factors affecting the formation and antioxidant activities

In order to establish an efficient detection method to evaluate the formation of Amadori compounds (ACs) in food products and study the potential health effects, an ultra-high performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method using caffeine as internal standard was developed to determine eight ACs. The detection limits ranged from 0.0179 to 0.0887 mg/L for the ACs. The accuracy of the method was tested through measuring recovery of the spiked samples that varied from 81.90 ± 2.98% to 108.74 ± 2.34%. This method was further applied to detect ACs in 10 food products. Results showed that dry fruits and vegetables were rich in ACs, the total content of ACs varied from 1.36 ± 0.26 to 3415.91 ± 147.96 mg/100 g. The total amount of ACs in tomato juice heated under vacuum condition showed significant increment (P < 0.05) in 25 min at 80 °C comparing with that under atmospheric pressure due to the rapid loss of water. Besides, the amino acid content shows positive correlation with the corresponding AC formation in Maillard reaction during food drying. After heated at fixed water activity (Aw) for 4 hr by sous-vide process, the ACs content in tomato powder increased significantly and the antioxidant activity improved as well. PRACTICAL APPLICATION: Results of this study provided a valuable tool to evaluate the formation of ACs in complex dry food products, facilitated the quality control of food products. The knowledge obtained will offer useful information to food processors. The synthesized ACs would facilitate further study into the antioxidant activities and potential health effects of specified AC.

Ultrasound-mediated fucoxanthin rich oil nanoemulsions stabilized by κ-carrageenan: Process optimization, bio-accessibility and cytotoxicity

This work aims to produce and optimize a κ-carrageenan-based nanoemulsion (NE) to encapsulate seaweed oil, which is rich in fucoxanthin (FX), using ultrasound-assisted emulsification. κ-Carrageenan was produced using subcritical water, and seaweed oil was extracted using supercritical carbon dioxide with sunflower oil as the co-solvent. Response surface methodology (RSM) was used to understand the influence of several process parameters such as ultrasound amplitude, time, temperature, and duty cycle to produce an NE. The RSM factor was used to focus on droplet size, polydispersity index, zeta potential, viscosity, antioxidant, FX, encapsulation efficiency, and emulsion stability. Our outcomes suggested that the ultrasound process had a noteworthy influence on the NE. The best conditions to obtain an NE were an ultrasound amplitude of 87 µm, a sonication time of 394 s, a temperature of 60 °C, and a duty cycle of 50%. The resulting NE was studied by UV-Vis, Fourier-transform infrared spectroscopy, thermal gravimetric analysis, differential scanning calorimetry, scanning electron microscopy, atomic force microscopy, and X-ray diffraction. Moreover, the NE obtained from optimized conditions was checked for fatty acid content, color, oxidative stability, in vitro digestion, bioaccessibility of FX, and cytotoxicity. The results obtained suggest that lower droplet size of the emulsion can improve oxidative stability, in vitro digestion, bioaccessibility of FX, and good cell inhibition against a few cell lines. Therefore, a κ-carrageenan-stabilized NE can be used as a potential delivery system to endorse applications of seaweed oil, which is rich in FX, in functional foods, beverage systems, and pharmaceuticals.

Effects of in vitro Human Digestion on the Antioxidant Activity and Stability of Lycopene and Phenolic Compounds in Pork Patties Containing Dried Tomato Prepared at Different Temperatures

The antioxidant activity can be changed during digestion. The effects of in vitro human digestion on the antioxidant activity and stability of tomato powders (TPs), dried at three different temperatures (60, 80, and 100 °C) and added to pork patties (1% TP by weight), were investigated. The pork patties with three TPs underwent in vitro human digestion with enterobacteria. Lycopene and individual phenolic compounds were analyzed by using HPLC. The highest total phenolic compounds (6.96 g/100 g) and lycopene concentrations (2.68 mg/100 g) were observed in pork patties with TP dried at 100 °C. In addition, antioxidant activity of pork patties containing TPs were measured during in vitro human digestion. Gallic acid (23.8 to 41.6 g/100 g), chlorogenic acid (11.2 to 25.7 g/100 g), and caffeic acid (11.1 to 21.7 g/100 g) were detected as the main phenolic compounds in the TPs. Lycopene, and total and individual phenolic compound contents increased with increasing drying temperatures. Moreover, in vitro human digestion increased the antioxidant activity of TP-containing pork patties. The lycopene and total phenolics contents were increased during in vitro human digestion with enterobacteria by 146% to 220% and 1549% to 2095%, respectively as compared to the samples of before digestion. Hence, we hypothesized that the antioxidant activity of each TP increased during in vitro human digestion and depended on the amount of lycopene and phenolic compounds released. The TP dried at the highest temperature (100 °C) had the highest antioxidant activity in pork patties during in vitro human digestion.

PRACTICAL APPLICATION

In this study, we revealed that in vitro human digestion increases the antioxidant activities of tomato powder. In addition, tomato powder dried at the highest temperature (100 °C) showed the highest antioxidant activity. Therefore, tomato powder at 100 °C could be used as strong antioxidants in meat products.

Evolution of the oxidative stability, bio-active compounds and color characteristics of non-thermally treated vegetable pâtés during frozen storage

BACKGROUND

Few studies have investigated the effects of frozen storage on processed vegetables. The present study evaluates its effects on the quality characteristics of non-thermally stabilized tomato-based pâtés compared to thermally stabilized pâtés stored at room temperature. Two different types of tomato-based pâtés were analyzed in terms of bio-active compounds, as well as colorimetric parameters and oxidative degradation just after processing and also after 4, 8 and 12 months of storage.

RESULTS

Thermal treatment mainly affected the colorimetric parameters and oxidative degradation, whereas its effects on bio-active compounds became more visible and significant during storage. Freezing allowed in both pâtés to maintain significantly higher a* values than storage at room temperature, whereas brightness, which is linked to residual activities of different enzymes, varied during storage according to the ingredient formulation. During storage, oxidative degradation of the lipid fraction was more marked in the pâté containing a lower quality oil, and less marked when the absence of thermal treatment was combined with frozen storage.

CONCLUSION

Freezing could represent a viable alternative way to preserve high-quality products over time. An optimal combination of blanching, freezing rate, storage and thawing conditions will provide the best results in terms of the quality/price ratio. © 2017 Society of Chemical Industry.

Effect of reciprocating agitation thermal processing (RA-TP) on quality of canned tomato (Solanum lycopersicum) puree

BACKGROUND

Reciprocating agitation thermal processing (RA-TP) is a recent innovation in the field of canning for obtaining high-quality canned food. The objective of this study was to compare RA-TP processing with conventional non-agitated (still) processing with respect to the impact on quality (color, antioxidant capacity, total phenols, carotenoid and lycopene contents) of canned tomato (Solanum lycopersicum) puree.

RESULTS

Owing to a 63-81% reduction in process times as compared with still processing, tomato puree with a brighter red color (closer to fresh) was obtained during RA-TP. At 3 Hz reciprocation frequency, the loss of antioxidant, lycopene and carotenoid contents could be reduced to 34, 8 and 8% respectively as compared with 96, 41 and 52% respectively during still processing. In fact, the phenolic content for RA-TP at 3 Hz was 5% higher than in fresh puree. Quality retention generally increased with an increase in frequency, although the differences were less significant at higher reciprocation frequencies (between 2 and 3 Hz).

CONCLUSION

Research findings indicate that RA-TP can be effective to obtain thermally processed foods with high-quality attribute retention. It can also be concluded that a very high reciprocation frequency (>3 Hz) is not necessarily needed and significant quality improvement can be obtained at lower frequencies (∼2 Hz). © 2016 Society of Chemical Industry.

Evaluation of different drying temperatures on physico-chemical and antioxidant properties of water-soluble tomato powders and on their use in pork patties

BACKGROUND

Tomato and tomato products provide various antioxidant activities, which could be changed by the processing method. This study was performed to evaluate the antioxidant activity of water-soluble tomato powder (WSTP) as affected by different oven temperatures (60, 80 and 100°C), and to evaluate the physico-chemical properties and antioxidative activities of pork patties containing these powders.

RESULTS

The contents of total phenolic compounds of WSTP ranged from 22.2 to 69.6 g kg(-1) dry matter. The antioxidant activities increased significantly with increasing drying temperatures (P < 0.05). The physico-chemical properties of pork patties containing tomato powders were also evaluated. WSTP at 100°C showed the highest redness value compared to those dried at 60 and 80°C. Lipid oxidation of pork patties was retarded by 7 days with the addition of WSTP. In particular, pork patties containing WSTP showed antimicrobial activity at 14 days of refrigerated storage, regardless of drying temperatures.

CONCLUSION

WSTP, especially prepared at 100°C, could be used as a natural antioxidant and antimicrobial agent in meat products.

Processing of tomato: impact on in vitro bioaccessibility of lycopene and textural properties

BACKGROUND

Human studies have demonstrated that processing of tomato can greatly increase lycopene bioavailability. However, the difference between processing methods is not widely investigated. In the current study different thermal treatments of tomato were evaluated with regard to their impact on in vitro bioaccessibility and retention of lycopene and beta-carotene as well as textural properties. Thermal treatments used were low (60 degrees C) and high (90 degrees C) temperature blanching followed by boiling.

RESULTS

Lycopene was relatively stable during thermal treatment, whereas beta-carotene was significantly (P < 0.05) reduced by all heat treatments except for low temperature blanching. In vitro bioaccessibility of lycopene was significantly increased from 5.1 +/- 0.2 to 9.2 +/- 1.8 and 9.7 +/- 0.6 mg kg(-1) for low and high temperature blanching, respectively. An additional boiling step after blanching did not further improve lycopene bioaccessibility for any treatment, but significantly reduced the consistency of low temperature treated samples.

CONCLUSION

Choice and order of processing treatments can have a large impact on both lycopene bioavailability and texture of tomato products. Further investigations are needed, but this study provides one of the first steps towards tomato products tailored to optimise nutritional benefits.

Carotenoids: actual knowledge on food sources, intakes, stability and bioavailability and their protective role in humans

Carotenoids are one of the major food micronutrients in human diets and the overall objective of this review is to re-examine the role of carotenoids in human nutrition. We have emphasized the attention on the following carotenoids present in food and human tissues: beta-carotene, beta-cryptoxanthin, alpha-carotene, lycopene, lutein and zeaxanthin; we have reported the major food sources and dietary intake of these compounds. We have tried to summarize positive and negative effects of food processing, storage, cooking on carotenoid content and carotenoid bioavailability. In particular, we have evidenced the possibility to improve carotenoids bioavailability in accordance with changes and variations of technology procedures.

Determination of pigments in vegetables

Plant pigments are responsible for the shining color of plant tissues. They are also found in animal tissues and, eventually in transformed food products as additives. These pigments have an important impact on the commercial value of products, because the colors establish the first contact with the consumer. In addition plant pigments may have an influence on the health of the consumers. Pigments are labile: they can be easily altered, and even destroyed. Analytical processes have been developed to determine pigment composition. The aim of this paper is to provide a brief overview of these methods.

Alterations of vitamin C, total phenolics, and antioxidant capacity as affected by processing tomatoes to different products

This study was conducted to investigate the antioxidant vitamin C, the polyphenol content, and the hydrophilic antioxidant capacity of tomato juice, baked tomatoes, tomato sauce, and tomato soup. During the production of tomato juice and during the preparation of the other tomato products, samples were taken after different times, respectively, after each particular production step. High-performance liquid chromatography was used to determine the content of vitamin C. The total phenolics content was analyzed spectrophotometrically by using the Folin-Ciocalteu method. The hydrophilic antioxidant capacity was measured by using three different methods: the Trolox equivalent antioxidant capacity assay, the ferric reducing antioxidant power test, and the photochemiluminescence assay. The vitamin C contents of the tomato products decreased during the thermal processing of tomatoes. In contrast, the total phenolics concentration and the water soluble antioxidant capacity increased.