Effect of thermal and high pressure processing on antioxidant activity and instrumental colour of tomato and carrot purées

Effects of high hydrostatic pressure and soaking solution on proximate composition, polyphenols, anthocyanins, β-carotene, and antioxidant activity of white, orange, and purple fleshed sweet potato flour

Effects of high hydrostatic pressure (100, 200, and 400 MPa) and soaking solution (citric acid, calcium chloride, ascorbic acid, and distilled water) on proximate composition, polyphenols, anthocyanins, β-carotene, and antioxidant activity of white, orange, and purple fleshed sweet potato flour were investigated. Total polyphenol content was increased in sweet potato flour of Jishu 98 (white) at 200 MPa with ascorbic acid and Pushu 32 (orange) at 0.1 MPa with ascorbic acid treatment (0.51 and 0.83 mg gallic acid equivalent/g dry weight, respectively), but was decreased in Xuzishu No. 3 (purple) in both high hydrostatic pressure and soaking solution treatments. Total anthocyanin content was declined in all treated sweet potato flour. Nevertheless, high hydrostatic pressure with citric acid, calcium chloride, and distilled water significantly increased the β-carotene content in Pushu 32. Correlation analysis between total polyphenol content, total anthocyanin content, and antioxidant activity suggested that polyphenols are the most pivotal antioxidant in sweet potato flour. High hydrostatic pressure and soaking solution treated sweet potato flour could be potentially utilized in food with acceptable nutritional values.

The Effect of High Pressure Processing on Polyphenol Oxidase Activity, Phytochemicals and Proximate Composition of Irish Potato Cultivars

Polyphenol oxidase (PPO) activity, proximate composition, and phytochemicals were determined in four common Irish potato cultivars following a high pressure processing (HPP) at 600 MPa for 3 min. PPO activity was significantly (p < 0.05) lower in all HPP treated samples, while the overall proximate composition was not affected. The total phenolic content was significantly higher in the HPP treated samples. Chlorogenic acid levels significantly decreased with simultaneous increase of caffeic acid and p-coumaric acid levels upon HPP treatment. No significant changes were observed in rutin and ferulic acid levels, although their levels varied, depending on the potato cultivars, while the levels of cytotoxic glycoalkaloids (α-solanine and α-chaconine) remained unaltered.

Targeting hallmarks of cancer with a food-system-based approach

Although extensive resources are dedicated to the development and study of cancer drugs, the cancer burden is expected to rise by about 70% over the next 2 decade. This highlights a critical need to develop effective, evidence-based strategies for countering the global rise in cancer incidence. Except in high-risk populations, cancer drugs are not generally suitable for use in cancer prevention owing to potential side effects and substantial monetary costs (Sporn, 2011). There is overwhelming epidemiological and experimental evidence that the dietary bioactive compounds found in whole plant-based foods have significant anticancer and chemopreventative properties. These bioactive compounds often exert pleiotropic effects and act synergistically to simultaneously target multiple pathways of cancer. Common bioactive compounds in fruits and vegetables include carotenoids, glucosinolates, and polyphenols. These compounds have been shown to target multiple hallmarks of cancer in vitro and in vivo and potentially to address the diversity and heterogeneity of certain cancers. Although many studies have been conducted over the past 30 y, the scientific community has still not reached a consensus on exactly how the benefit of bioactive compounds in fruits and vegetables can be best harnessed to help reduce the risk for cancer. Different stages of the food processing system, from "farm-to-fork," can affect the retention of bioactive compounds and thus the chemopreventative properties of whole foods, and there are opportunities to improve handling of foods throughout the stages in order to best retain their chemopreventative properties. Potential target stages include, but are not limited to, pre- and postharvest management, storage, processing, and consumer practices. Therefore, there is a need for a comprehensive food-system-based approach that not only taking into account the effects of the food system on anticancer activity of whole foods, but also exploring solutions for consumers, policymakers, processors, and producers. Improved knowledge about this area of the food system can help us adjust farm-to-fork operations in order to consistently and predictably deliver desired bioactive compounds, thus better utilizing them as invaluable chemopreventative tools in the fight to reduce the growing burden of cancer worldwide.

Effects of ultrahigh pressure and ultrasound pretreatments on properties of strawberry chips prepared by vacuum-freeze drying

The present work investigated the influences of ultrahigh pressure (UHP), ultrasound (US) and their combination (UHP-US) as pretreatments on properties of vacuum-freeze dried strawberry slices. During vacuum-freeze drying, drying duration and total energy consumption of UHP sample, US sample and UHP-US sample was decreased. After the UHP or US pretreatments, a* value (redness), antioxidative substances (total anthocyanin content, total flavonoid content, total phenolic content, diphenyl picrylhydrazyl (DPPH), hydroxyl (-OH) radical-scavenging assay), hardness and cross-section areas of matrix in the dried slices were significantly (P < 0.05) increased. Transverse relaxation times and peak area corresponding to free water in the pretreated samples were obviously decreased, indicating lower mobility in the pretreated samples. As compared with UHP or US individually, UHP in combination with US increased those parameters more pronouncedly. Therefore, UHP and US are promising techniques for the vacuum-freeze drying processing of strawberry products.

Comparative Effects of Thermal, High Hydrostatic Pressure, and UV-C Processing on the Quality, Nutritional Attributes, and Inactivation of Escherichia coli, Salmonella, and Listeria Introduced into Tiger Nut Milk

HIGHLIGHTS

Thermal and nonthermal methods can support a 5-log CFU reduction of model bacteria introduced into tiger nut milk. Thermal treatment of tiger nut milk results in significant loss of protein, antioxidants, and quality properties. HHP or UV-C treatment of tiger nut milk retains quality and nutritional characteristics. HHP or UV-C are suitable for the pasteurization of tiger nut milk.

Effect of processing on quality attributes and phenolic profile of quince dried bar snack

BACKGROUND

Fruit and vegetable processing can often alter and damage antioxidants. Phenolic compounds, which are major antioxidants in these products, can suffer dissociation and changes in their concentration. Quince is an excellent source of antioxidants, with health-improving potential for consumers. The phenolic profile (by ultra-high-performance liquid chromatography-mass spectrometry) and quality attributes (pH, soluble solids, acidity, water activity) were determined for processed quince products (fresh fruit puree, cooked puree and dried bars), in addition to the effect of puree cooking time (5, 10, 15 and 20 min).

RESULTS

Soluble solids in purees averaged 14.4 °Brix and increased to 75 °Brix in bars, as did titratable acidity, reaching 1.5 g malic acid kg^-1 fresh weight after 20 min of cooking at 120 °C. Quercetin, p-coumaric acid and trans-cinnamic acid were predominant in fresh fruit puree. Thermal processing significantly increased the concentration of p-coumaric acid, trans-cinnamic acid, apigenin and quercetin, and decreased gallic acid. This increase was 242%, on average, for all of them when comparing fresh fruit puree with bars on a fresh weight basis, demonstrating their concentration throughout the dehydration process during bar production.

CONCLUSION

Although a minimum puree cooking time of 5 min was sufficient to obtain the highest concentration of most phenolics, p-coumaric acid showed a higher concentration after 20 min of cooking. © 2018 Society of Chemical Industry.

(Ultra) High Pressure Homogenization Potential on the Shelf-Life and Functionality of Kiwifruit Juice

The increasing competition within the food industry sector makes the requisite of innovation in processes and products essential, leading to focus the interest on the application of new processing technologies including high pressure homogenization (HPH) and ultra high pressure homogenization (UHPH). In this context, the present research aimed at evaluating the effects of two UHPH treatments performed at 200 MPa for 2 and 3 cycles on quality and functionality of organic kiwifruit juice stored at three different temperatures, i.e., 5, 15, and 25°C. The results showed that only the treatment performed at 200 MPa for 3 cycles was able to significantly increase the shelf-life of organic kiwifruit juices when stored at refrigeration temperature, avoiding also phase separation that occurred in the sample treated at 0.1 MPa (control) after 20 days of refrigerated storage. The obtained data showed also that the highest applied pressure was able to increase some quality parameters of the juice such as viscosity and luminosity (L^∗) and increased the availability of total phenol content consequently enhancing the juice total antioxidant activity. The application of a treatment at 200 MPa for 3 cycles allowed to obtain a stable kiwifruit juice for more than 40 days under refrigerated storage. A challenge to implement this technology in food process as full alternative to thermal treatment could be represented by the adoption of pressure level up to 400 MPa followed by the packaging in aseptic conditions.

Long-Term Effect on Bioactive Components and Antioxidant Activity of Thermal and High-Pressure Pasteurization of Orange Juice

The long-term effect of thermal pasteurization (TP) and high-pressure processing (HPP) of orange juices stored under refrigeration, on the bioactive components and antioxidant activity, was compared. Total phenolic content (TPC), flavonoid, anthocyanin, and carotenoid contents, the individual content of major phenolic components, and the antioxidant activity, were evaluated in TP- and HPP-treated juices over a 36-day period. At day 0, no significant differences in TPC, and a decrease in carotenoid content after both treatments, were observed. TP caused a decrease of flavonoid and anthocyanin contents, while HPP increased flavonoid content. Three major phenolic components were identified: apigenin-6,8-di-C-glucoside, naringenin-7-O-rutinoside, and hesperetin-7-O-rutinoside, the latter increasing ca. 45% immediately after HPP. During storage, a decrease in TPC, and in the anthocyanin and carotenoid contents of both treated juices was observed, with higher anthocyanin and phenolic contents in HPP juices. A significant increase of hesperetin-7-O-rutinoside content was observed in HPP juice. Both treatments caused a decrease (26% and 13%, respectively) of antioxidant activity. Most of the kinetic profiles followed zero-order patterns, with HPP juices showing a considerably higher half-life than TP ones. These results clearly demonstrate the advantages of HPP for orange juice preservation allowing, also, their nutritional benefits to be enhanced by increasing the content of some bioactive components.

Application of high hydrostatic pressure on Pacific white shrimp (Litopenaeus vannamei) pâté: Microbiological, physicochemical and consumer acceptance

The locally elaborated shrimp pâté is highly susceptible to microbial spoilage and deterioration during storage due to its content in nutrients. These conditions limit its commercialization in a larger scale. High hydrostatic pressure is an alternative to heat treatments technology used to inactivate microorganisms. The aim of this project was to evaluate the effect of high hydrostatic pressure on quality parameters and microbiological stability of Pacific white shrimp ( Litopenaeus vannamei) pâté during storage. Shrimp pâté was pressurized to 400, 500 and 600 MPa for 90 and 180 s. Samples were analysed for physicochemical, microbiological and flavour profile up to 21 days of storage at 4 ℃. A hedonic test was made to evaluate the acceptance of pâté. No microorganisms were detected at 600 MPa for 180 s and a shelf life of 14 days was reached. No relevant changes in pH or colour of pressurized samples were detected; flavour profile did not show any changes after being pressurized or during storage. Shrimp pâté treated with 600 MPa for 180 s presented good sensory acceptance. High hydrostatic pressure treatments could improve microbiological quality of shrimp pâté without a sensible modification of the physicochemical and sensorial qualities of this product.

Effect of various food processing and handling methods on preservation of natural antioxidants in fruits and vegetables

Bioactive compounds from plant sources are generally categorized as natural antioxidants with well-known health benefits. The health-promoting characteristics of natural antioxidants include anti-inflammatory, anti-diabetic, and hepatic effects as well as free radical scavenging. Herein, a comprehensive and comparative review are presented about the effects of conventional (thermal and mechanical) and relatively new (non-thermal) processing methods on phytochemicals and discussed the importance of implementing the use of those methods that could be of very helpful retaining the quality of the bioactive compounds in plant-based foods. Plant-based foods rich in phenolics, vitamin C, carotenoids, and other compounds undergo a range of processing operations before they are consumed. Most of these methods involve thermal treatments of fruits, stems, leaves, and roots. These techniques have varying effects on bioactive compounds and their activities, and the magnitude of these effects depends on process parameters such as temperature, time, and the food matrix. Thermal processing can be detrimental to bioactive compounds while nonthermal procedures may not cause significant deterioration of important health-promoting phytochemicals and in some cases can improve their bio-activity and bio-availability. The detrimental effects of conventional processing on the quality of natural antioxidants have been compared to the effects of innovative nonthermal food treatments such as gamma and ultraviolet irradiation, ultraviolet light, pulsed electric fields, and high hydrostatic pressure.

Kinetics of inactivation of quality-deteriorating enzymes and degradation of selective phytoconstituents in pink guava pulp during thermal processing

Thermal inactivation kinetics of peroxidase (POD), polyphenol oxidase (PPO), pectin methyl esterase (PME) and ascorbate oxidase (AO) were studied over the temperature range of 45-85 °C along with the degradation kinetics of ascorbic acid (AA) and lycopene in Psidium guajava pulp. POD, PPO, PME and AO followed first-order kinetics whereas AA degradation data was explained by pseudo first-order kinetics. Lycopene degradation was suitably fitted in an exponential model, indicating continuous degradation of lycopene and higher degradation at higher temperature. Activation energy (Ea) of POD, PPO, PME, and AO was 63.79 ± 1.28, 60.36 ± 1.21, 63.22 ± 1.06 and 106.33 ± 8.51 kJ/mol, respectively. AA had Ea (95.82 ± 1.92 kJ/mol) higher than lycopene (54.92 ± 1.10 kJ/mol). PME (Z = 39.4 ± 0.1 °C) showed highest heat stability while AO (Z = 14.3 ± 1.1 °C) was least stable amongst the enzymes studied. AA (Z = 23.5 ± 0.5 °C) was weakest amongst the phytoconstituents in guava pulp and its retention was challenged during thermal processing. The thermal resistance of quality deteriorating enzyme of guava was found to be higher than that of the common spoilage organisms such as Saccharomyces cerevisiae and Lactobacillus plantarum reported for processed fruit products. Thus, this research hints towards the need for more robust thermal processing for inactivation of quality deteriorating enzymes.

Effect of Microwave Vacuum Drying on the Drying Characteristics, Color, Microstructure, and Antioxidant Activity of Green Coffee Beans

The aim of this study is to investigate the effect of microwave vacuum drying (MVD) on the drying characteristics and quality attributes of green coffee beans. We specifically focused on the effective moisture diffusion coefficient (D_eff), surface temperature, glass transition temperature (T_g), water state, and microstructure. The kinetics of color changes during drying, total phenolic content (TPC), and antioxidant activity (DPPH, FRAP, and ABTS) were also characterized. Microwave power during MVD affected the porosity of coffee beans, their color, TPC, and antioxidant activity. The Allometric 1 model was the most suitable for simulating surface temperature rise kinetics. Thermal processing of green coffee beans resulted in increased b*, L*, ΔE, and TPC values, and greater antioxidant capacity. These findings may provide a theoretical reference for the technical improvement, mechanisms of flavor compound formation, and quality control of dried green coffee beans.

Enhancing the physicochemical stability of β-carotene solid lipid nanoparticle (SLNP) using whey protein isolate

β-Carotene is a nutraceutical that acts as a coloring agent and as pro-vitamin A, but its incorporation into foods is limited because of its hydrophobicity and low chemical stability. The aim of this study was to improve the physicochemical stability of β-carotene by encapsulating into solid lipid nanoparticles (SLNPs) containing palmitic acid and corn oil, stabilized using whey protein isolate (WPI). The palmitic acid crystals covered the surface of the oil droplets and formed a solid shell to protect the encapsulated β-carotene. Corn oil decreased the exclusion of β-carotene from the solid lipid matrix to the surface of SLNPs. WPI increased the colloidal stability of the system, and improved β-carotene oxidative stability. The rate of color fading due to β-carotene degradation increased with increasing temperature and was faster at lower pH. Lower ionic strengths had a slight impact on β-carotene degradation, while higher ionic strengths accelerated β-carotene breakdown.

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.

Stability of bioactive compounds in butiá (Butia odorata) fruit pulp and nectar

Butia odorata is a palm tree native to southern Brazil whose fruit (known as butiá) and leaves are used to make many food products and crafts. Butiá contain several biologically active compounds with potential health benefits. However, processing conditions can alter quality attributes including bioactive compound content. This study evaluated the stability of bioactive compounds in butiá pulp upon pasteurization, during 12months of frozen storage, and in butiá nectar after a 3-month storage period. Pulp pasteurization resulted in a reduction in phenolic, flavonoid, carotenoid, and ascorbic acid contents. After a 12-month frozen storage period, flavonoid, phenolic, and ascorbic acid contents decreased while carotenoid content remained unaltered. Carotenoid, ascorbic acid, and phenolic contents were unaffected by the 3-month storage of butiá nectar; however, flavonoid content and antioxidant potential were reduced. Despite bioactive compound degradation upon heat treatment and storage, butiá nectar remained rich in phenolics, especially (-)-epicatechin, rutin, and (+)-catechin.

Influence of High Hydrostatic Pressure Technology on Wine Chemical and Sensorial Characteristics: Potentialities and Drawbacks

During last years, scientific research on high hydrostatic pressure (HHP) as a nonthermal processing technology for preservation or aging of wine has increased substantially. HHP between 200 and 500MPa is able to inactivate bacteria and yeasts in red and white wines, suggesting that it may be used for wine preservation. However, these treatments have been shown to promote changes on sensorial and physicochemical characteristics in both red and white wines, not immediately in the first month, but along storage. The changes are observed in wine color, aroma, and taste due mainly to reactions of phenolic compounds, sugars, and proteins. These reactions have been associated with those observed during wine aging, leading to aged-like wine characteristics perceived by sensorial analysis. This chapter will present the influence of HHP technology on wine chemical and sensorial characteristics, criticaly discussing its potentialities and drawbacks. The appropriate use of HHP, based on the scientific knowledge of the reactions occuring in wine promoted by HHP, will allow to exploit this technology for wine production achieving distinct characteristics to address particular market and consumer demands.