The impact of food processing on antioxidants in vegetable oils, fruits and vegetables

New Strategy for Browning Prevention in Apple Pomace Processing and Toxicity Tested in a Rodent Model

Apple pomace (AP) is a byproduct of apple juice industries, which constitutes around 30% of the original fruit and rich in essential compounds like carbohydrates, phenolics, minerals, and dietary fibers. This study is focused on optimizing the combinational utilization of antibrowning agents like l-cysteine and l-ascorbic acid for the sustainable debrowning of AP with response surface methodology and assessment of its acute toxicity in female rats. In addition, the phytochemical content and antioxidant activity of treated AP were investigated and compared with the untreated control AP. The study revealed that the treated AP has higher dietary fiber (p < 0.01), protein (p < 0.0001), and phenolic content (p < 0.001) in comparison to the control AP. Moreover, the treated AP also observed with higher antioxidant activity 37% inhibition and water retention capacity (8.5 g H2O/g solid) along with the debrowning effect. Furthermore, a 4-week in vivo study is conducted to assess the toxicity of treated AP. Results indicated no discernible variations in biochemistry, morphometric, or histology between the supplementation (0.5, 1.5, and 3% AP) and control groups. Thus, adding AP rich in dietary fiber to a range of meals is deemed a safe and valuable food supplement.

Changes in the antioxidant and anti-inflammatory activities of Rosa rugosa 'Mohong' during fermentation

Fermented rose petals are a traditional delicacy of the Dali Bai community in Yunnan, China. Fermentation enhances the quality and nutritional value of roses, as well as their efficacy, by increasing the levels of phenolic compounds. This study aimed to investigate the significant variations in four active compounds throughout the traditional fermentation process. Four compounds in Rosa rugosa 'Mohong' were examined, and significant variations among polyphenols and antioxidant and anti-inflammatory activities were observed. These variations were studied during fermentation by Saccharomyces rouxii at varying temperatures and durations. Moreover, the results showed that gallic acid and syringic acid content significantly increased (P < 0.05) with a rise in temperature from 20°C-35 °C during fermentation. Simultaneously, rutin and quercetin levels significantly decreased (P < 0.05) at all four temperatures throughout the five periods. The antioxidant and anti-inflammatory activities of fermented R. rugosa 'Mohong' methanol extracts were dose-dependent. Our results provide valuable insights into optimizing the processing scale and quality control of fermented rose products.

Antioxidant and Anti-Inflammatory Properties of Quail Yolk Oil via Upregulation of Superoxide Dismutase 1 and Catalase Genes and Downregulation of EIGER and Unpaired 2 Genes in a D. melanogaster Model

Quail egg yolk oil (QEYO) has a rich history of medicinal use, showcasing heightened antioxidant and bioactive properties in our prior studies. This positions QEYO as a promising candidate for therapeutic and cosmetic applications. In this investigation, QEYO was extracted using ethanol/chloroform and 2-propanol/hexane solvents. GC-MS and FTIR analyses quantified 14 major bioactive compounds in the ethanol/chloroform fraction and 12 in the 2-propanol/hexane fraction. Toxicity evaluations in fruit flies, spanning acute, sub chronic, and chronic exposures, revealed no adverse effects. Negative geotaxis assays assessed locomotor activity, while biochemical assays using fly hemolymph gauged antioxidant responses. Real-time PCR revealed the relative expression levels of the antioxidant and anti-inflammatory genes. FTIR spectra indicated diverse functional groups, and the GC-MS results associated bioactive compounds with the regulation of the anti-inflammatory genes EIGER and UPD2. While no significant change in SOD activities was noted, male flies treated with specific QEYO doses exhibited increased catalase activity and total antioxidant capacity, coupled with a significant decrease in their malondialdehyde levels. This study offers valuable insights into the bioactive compounds of QEYO and their potential regulatory roles in gene expression.

Effect of pre-treatment and freezing on the polyphenol oxidase activity and color stability of sliced peaches

BACKGROUND

A study was conducted to determine the polyphenol oxidase (PPO) activity and changes in surface color and hydroxymethylfurfural (HMF) content in fresh and pre-frozen peach slices stored at different temperatures. In this study, fresh (F) and pre-frozen (P) peaches were subjected to one of four treatments: (i) no treatment (N); (ii) blanching in boiling (96 °C ± 4 °C) water (B); (iii) dipping in 2% l-ascorbic acid and 2% citric acid (AC); or (iv) blanching placed in boiling water, cooling and dipping in 2% ascorbic acid and 2% citric acid (BAC). Peaches from each treatment group were held at -7, -9, or - 12 °C for 21 days.

RESULTS

After 21 days of storage, PPO activity and browning was greater in peaches stored at -7 °C than the PPO activity and browning of peaches stored at -9 °C and - 12 °C. Overall, lightness (L*), yellowness (b*), chroma (c*) and hue (h*) decreased while redness (a*) increased during storage. The BAC peaches had less discoloration and lower PPO activity than peach slices exposed to other treatments. Non-enzymatic browning (HMF indicator) was more pronounced for blanched peaches during storage than unblanched peaches. Pretreatment of blanched peaches with ascorbic and citric acid reduced browning during 21 days at frozen storage for peaches held at -9 °C or - 12 °C.

CONCLUSION

Storage at -12 °C significantly reduced browning and HMF formation in both blanched and unblanched peach slices in comparison with -7 °C storage. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Recombinant Expression of Archaeal Superoxide Dismutases in Plant Cell Cultures: A Sustainable Solution with Potential Application in the Food Industry

Superoxide dismutase (SOD) is a fundamental antioxidant enzyme that neutralises superoxide ions, one of the main reactive oxygen species (ROS). Extremophile organisms possess enzymes that offer high stability and catalytic performances under a wide range of conditions, thus representing an exceptional source of biocatalysts useful for industrial processes. In this study, SODs from the thermo-halophilic Aeropyrum pernix (SOD_Ap) and the thermo-acidophilic Saccharolobus solfataricus (SOD_Ss) were heterologously expressed in transgenic tomato cell cultures. Cell extracts enriched with SOD_Ap and SOD_Ss showed a remarkable resistance to salt and low pHs, respectively, together with optimal activity at high temperatures. Moreover, the treatment of tuna fillets with SOD_Ap-extracts induced an extension of the shelf-life of this product without resorting to the use of illicit substances. The results suggested that the recombinant plant extracts enriched with the extremozymes could find potential applications as dietary supplements in the nutrition sector or as additives in the food preservation area, representing a more natural and appealing alternative to chemical preservatives for the market.

Soybean Oil Epoxidation Catalyzed by a Functionalized Metal–Organic Framework with Active Dioxo-Molybdenum (VI) Centers

In this work, a functionalized gallium metal–organic framework with active dioxo-molybdenum (VI) centers was evaluated as a catalyst in the epoxidation of soybean oil using tert-butyl-hydroperoxide as an oxidizing agent. The influence of the reaction time, temperature, and concentration of the oxidizing agent was studied, and it was demonstrated that the highest epoxide selectivity was obtained at 110 °C after 4 h of reaction (29% conversion and 91% selectivity) using a soybean oil/oxidizing agent ratio of 1/2. The stability of the metal–organic framework was confirmed by infrared spectroscopy, X-ray powder diffraction, thermogravimetric analysis, scanning electron microscopy, and energy-dispersive X-ray spectroscopy EDS. The stability tests demonstrated that the catalyst could be reused in the catalytic process for the recovery of vegetable oils.

Graphical Abstract

Anti-tyrosinase, antioxidant and antibacterial activities of gallic acid-benzylidenehydrazine hybrids and their application in preservation of fresh-cut apples and shrimps

A series of gallic acid-benzylidenehydrazine hybrids were synthesized and evaluated for their tyrosinase inhibitory activity. Thereinto, compounds 5d and 5f potently inhibited tyrosinase with IC₅₀ of 15.3 and 3.3 μM, compared to kojic acid (44.4 μM). The inhibition mechanism suggested that 5d and 5f not only chelated with Cu²⁺, but also reduced Cu²⁺ to Cu¹⁺ in the tyrosinase active site. Additionally, 5d and 5f exhibited strong DPPH scavenging and antibacterial activities against Vibrio parahaemolyticu and Staphylococcus aureus, which can be attributed to the function of gallic acid and hydrazone moiety. These compounds also exhibited capacity to preserve fresh-cut apples and shrimps. Finally, 5d and 5f exhibited low cytotoxic activity in a human cell line (HEK293). Therefore, these compounds possess anti-tyrosinase, antioxidant, and antibacterial activities, and can be used in the development of novel food preservatives.

Polyphenols, L-Ascorbic Acid, and Antioxidant Activity in Wines from Rose Fruits (Rosa rugosa)

The aim of the present study was to determine the influence of the winemaking process on the antioxidant potential and content of phenolic compounds and L-ascorbic acid in wines from the fruits of Rosa rugosa. The results obtained in this study clearly indicate that the fruits of the Rosa rugosa are a desirable raw material for the production of fruit wine. The parameters of the technological process of producing wines from rose fruits had a diversified influence on the tested quality characteristics. Aged wines contained phenolics levels of 473-958 mg/100 mL GAE. The final concentrations of ascorbic acid ranged from 61 to 155 mg/100 mL for the different variants of the wine. Wines revealed high antioxidant activity in assay with DPPH. On the basis of the obtained results, it can be assumed that all the applied variants of the winemaking process are suitable for rose fruit wine. Each variant ensured at least the stability of the antioxidant capacity.

Antioxidants, Food Processing and Health

The loss and/or modification of natural antioxidants during various food processing techniques and storage methods, like heat/thermal, UV, pulsed electric field treatment, drying, blanching and irradiation is well described. Antioxidants in their reduced form are modified mainly by oxidation, and less by pyrolysis and hydrolysis. Thus, they are chemically converted from the reduced to an oxidized form. Here we describe the neglected role of the oxidized forms of antioxidants produced during food processing and their effect on health. While natural antioxidants in their reduced forms have many well studied health-promoting characteristics, much less is known about the effects of their oxidized forms and other metabolites, which may have some health benefits as well. The oxidized forms of natural antioxidants affect cell signaling, the regulation of transcription factor activities and other determinants of gene expression. Very low doses may trigger hormesis, resulting in specific health benefits by the activation of damage repair processes and antioxidative defense systems. Functional studies determining the antioxidants’ effects on the organisms are important, especially as reduced or oxidized antioxidants and their metabolites may have additional or synergistic effects.

Recent Trends in Controlling the Enzymatic Browning of Fruit and Vegetable Products

Enzymatic browning because of polyphenol oxidases (PPOs) contributes to the color quality of fruit and vegetable (FV) products. Physical and chemical methods have been developed to inhibit the activity of PPOs, and several synthetic chemical compounds are commonly being used as PPO inhibitors in FV products. Recently, there has been an emphasis on consumer-oriented innovations in the food industry. Consumers tend to urge the use of natural and environment-friendly PPO inhibitors. The purpose of this review is to summarize the mechanisms underlying the anti-browning action of chemical PPO inhibitors and current trends in the research on these inhibitors. Based on their mechanisms of action, chemical inhibitors can be categorized as antioxidants, reducing agents, chelating agents, acidulants, and/or mixed-type PPO inhibitors. Here, we focused on the food ingredients, dietary components, food by-products, and waste associated with anti-browning activity.

The effect of postharvest ultraviolet irradiation on the content of antioxidant compounds and the activity of antioxidant enzymes in tomato

The effect of different doses of long-wavelength UV-A (320 nm-400nm) irradiation on physicochemical and antioxidant characteristics of tomatoes grown on the territory of the Russian Federation was studied. The obtained results show that this kind of processing does not cause deterioration of qualitative parameters of vegetables (texture, color, soluble solids content, titratable acidity). It was established that the total content of phenolic compounds, carotenoids and flavonoids increases (p-value<0.05) in tomatoes at all the investigated wavelengths (353 nm, 365 nm and 400 nm), while the content of chlorophylls reacts ambiguously: at some wavelengths, it increases, at other, it decreases. The maximum increase in antioxidant activity, as compared to untreated samples, is observed in tomatoe samples irradiated for 360 min within the range of 365 nm. For different types of tomatoes, the increment for common content of phenolic compounds is - 42.9-55.0 %, carotenoids - 24.0-56.0 %, flavonoids - 28.0-33.0 %, β-carotene - 70.9-71.6 %, lycopene - 62.6-69.0 %, lutein - 64.8-72.0 % from original. The studies reveal some potential of post-harvest ultraviolet irradiation (A-range) of tomatoes to increase their antioxidant activity. However, more research is needed to confirm this fact and the possibility to develop some technology.

Bioactive micro-constituents of ackee arilli (Blighia sapida K.D. Koenig)

Ackee (Blighia sapida K. D. Koenig) is an exotic fruit widely consumed in the Caribbean countries. While there is extensive research on the presence of hypoglycin A, other bioactive compounds have not been studied. We identified and quantified the changes in bioactive molecules (total phenol, ascorbic acid, hypoglycin A, squalene, D: A-Friedooleanan-7-ol, (7.alpha.), and oleic acid), antioxidant potential, and volatile compounds during two stages of ripe. A clear reduction in hypoglycin A, ascorbic acid, and total polyphenols during the maturation process were observed. On the contrary, oleic acid, squalene, and D: A-Friedooleanan-7-ol, (7.alpha.) contents increased about 12, 12, and 13 times, respectively with advancing maturity. These bioactive molecules were positively correlated with radical scavenging (DDPH and ABTS). Solid phase microextraction (SPME) and gas chromatography coupled mass spectrometry (GC/MS) analysis revealed more than 50 compounds with 3-penten-2-one and hexanal as the major compounds in the fully ripe stage. The results suggested that ripe ackee arilli could serve as an appreciable source of natural bioactive micro-constituents.

Association of dietary total antioxidant capacity to anthropometry in healthy women: A cross-sectional study

OBJECTIVES

Reactive oxygen species level is a fundamental component in the pathogenesis of obesity that might be reduced by dietary antioxidants. Measurement of dietary total antioxidant capacity (DTAC) is regarded as a new holistic dietary index. Given the limited research on DTAC, the aim of this study was to examine the association of DTAC with obesity-related features in women.

METHODS

The present cross-sectional study included 627 female participants. Data on dietary intake were assessed using a validated food frequency questionnaire. DTAC was estimated through total reactive antioxidant potential (TRAP), Trolox equivalent antioxidant capacity (TEAC), and ferric reducing ability of plasma (FRAP). Anthropometric parameters (body mass index and waist circumference), were investigated using standard methods.

RESULTS

After adjustment for possible covariates, both TRAP and TEAC were significantly positively associated with obesity (TRAP: OR, 1.65; 95% confidence interval [CI], 1.04-2.63; P_trend, 0.03; TEAC: OR, 1.63; 95% CI, 1.01-2.63; P_trend, 0.04). However, there was no association between FRAP and obesity (OR_, 1.11; 95% CI, 0.64-1.93; P_trend, 0.68). Moreover, no relationship was found between different DTAC indices and waist circumference (TRAP: OR, 1.13; 95% CI, 0.70-1.80; P_trend, 0.60; TEAC: OR, 1.04; 95% CI, 0.64-1.69; P_trend, 0.87; FRAP: OR, 0.86; 95% CI, 0.49-1.51; P_trend, 0.62).

CONCLUSION

Women with higher DTAC scores had higher risk for obesity. No association was found between DTAC and waist circumference.

Biosynthesis of reusable and recyclable CuO@Magnetite@Hen Bone NCs and its antioxidant and antibacterial activities: a highly stable magnetically nanocatalyst for excellent reduction of organic dyes and adsorption of polycyclic aromatic hydrocarbons

For the first time, through a fast, eco-friendly and economic method, the aqueous extract of the leaf of Euphorbia corollate was used to the green synthesis of the highly stable CuO@Magnetite@Hen Bone nanocomposites (NCs) as a potent antioxidant and antibacterial agent against Pseudomonas aureus, Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae pathogenic bacteria. The biosynthesised NCs were identified using the scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy, elemental mapping, X-ray diffraction (XRD), Fourier transforms infrared spectroscopy and UV-vis analytical techniques. Also, the radical scavenging activity using (2,2-diphenyl-1-picrylhydrazyl) method was used to evaluate the antioxidant activity of the NCs. The stability of nanocatalyst was monitored using the XRD and SEM analyses after 30 days from its synthesis. Furthermore, its excellent catalytic activity, recycling stability, and high substrate applicability were demonstrated to the adsorption of the polycyclic aromatic hydrocarbons of the light crude oil from Shiwashok oil fields and destruction of methylene blue and methyl orange as harmful organic dyes at ambient temperature using UV-vis spectroscopy. Moreover, the green CuO@Magnetite@Hen Bone NCs were recovered and reused several times without considerable loss of its catalytic activity.

Effects of ZnO nanoparticles in the Caspian roach (Rutilus rutilus caspicus)

Most studies investigating the toxicity of zinc oxide nanoparticles (ZnO NPs) focused on the effect of size, whereas exposure concentration and duration remained poorly understood. In this study, the effect of acute and sub-acute exposures of ZnO NPs on Zn compartmentalization and biomarkers' expression were investigated in Rutilus rutilus caspicus (Caspian roach) considering various exposure scenarios: i) the assessment of the concentration-response curves and median lethal concentration (LC₅₀); ii) the assessment of the effects of organisms exposed at LC₅₀ value and one tenth of LC₅₀ value of ZnO NPs suspensions for 4 d and 28 d, respectively; iii) the assessment of 14 d depuration period. The same concentrations of ZnSO₄ were investigated. The highest Zn accumulation was detected in gill after sub-acute exposure (4.8 mg/L; 28 d) followed by liver, kidney and muscle. In gill, liver and muscle, Zn from Zn NPs accumulated higher concentrations. Depuration (14 d) decreased Zn content in each organ, but no complete removal occurred except for muscle. Biomarkers' activity was significantly over expressed after treatments, but depuration brought back their values to background levels and most effects were related to acute concentrations (48 mg/L; 4 d) and in presence of ZnSO₄. Histopathological analyses showed that the exposure to ZnO NPs increased lesions in gill, liver and kidney, with a direct proportionality between alterations and Zn accumulated in the target organs. After depuration, lesions regressed for both ZnO NPs and ZnSO₄, but not in a complete way. These data could contribute to increase the knowledge about ZnO NPs risk assessment in aquatic vertebrates, suggesting that the size of ZnO NPs can influence biomarker and histopathological effects.

Natural iron ore as a novel substrate for the biosynthesis of bioactive-stable ZnO@CuO@iron ore NCs: a magnetically recyclable and reusable superior nanocatalyst for the degradation of organic dyes, reduction of Cr(vi) and adsorption of crude oil aromatic compounds, including PAHs

For the first time, stable ZnO@CuO@iron ore nanocomposites (NCs) were green synthesized using magnetic iron ore as a natural substrate through an eco-friendly, simple and cost-effective method.

Instant vegetable from osmo-air drying of jimikand (A. campanulatus) in NaCl solution: nutritional, functional, micro-structural and other quality aspects

The aim of this work was to study the effect of osmotic dehydration on the quality of jimikand which can be used as an instant vegetable to get its nutritional and functional benefits. Osmotic dehydration was applied as pre-treatment to hot-air drying for increasing palatability, mass transfer improvement and minimizing nutritional losses. To see the effect of osmotic dehydration on various quality parameters, conditions of osmotic dehydration selected were osmotic solution concentrations (5, 10 and 15 % w/w) and temperatures (40, 50 and 60 °C) for constant process time (80 min) on the basis of mass transfer analysis. The observed values of hardness, oxalate content and water activity of osmo-dried samples varied from 66.04 ± 14.5 to 79.12 ± 14.8 N, 60.0 ± 0.40 to 69.1 ± 0.65 mg/100 g, 0.911 ± 0.001 to 0.826 ± 0.001, respectively, and found less as compared to fresh sample, i.e. 131.12 ± 9.5 N, 110.5 ± 0.78 mg/100 g and 0.990 ± 0.00 respectively. Rehydration ratio of fresh sample was 3.52 ± 0.03 and varied from 2.82 ± 0.06 to 3.57 ± 0.10 for osmo-dried samples being higher at lower concentrations and temperatures. The best conditions of osmotic dehydration found were 10 % NaCl, 50 °C temperature and 80 min duration on the basis of appreciable mass transfer, lowest oxalate content, water activity, better rehydration, textural and sensory quality. The selected osmo-dried sample was better due to low anti-nutritional content, less micro-structural damage and appreciably comparable to fresh hot-air dried in terms of total phenol, antioxidant activity, and other quality parameters.

Breads Fortified with Freeze-Dried Vegetables: Quality and Nutritional Attributes. Part II: Breads Not Containing Oil as an Ingredient

The present article describes the second part of a study investigating the effect of adding vegetables on the nutritional, physico-chemical, and oxidative properties of wheat bread, and specifically focuses on bread that does not contain oil as an added ingredient. Wheat flour breads fortified with freeze-dried carrot, tomato, beetroot or broccoli were developed and assessed for their nutritional composition, antioxidant potential, oxidative stability, and storage properties. Using a simulated in vitro model, the study also examined the impact of vegetable addition on the oxidative stability of macronutrients during gastro-intestinal digestion. Adding vegetables improved the nutritional and functional attributes of the oil-free breads. However, they demonstrated a lower antioxidant potential compared to their oil-containing counterparts. Similarly, the textural and storage properties of the oil-free vegetable breads were poorer compared to the oil-containing breads. As expected, in the absence of oil the oil-free breads were associated with lower lipid oxidation both in their fresh form and during gastro-intestinal digestion. Adding vegetables reduced protein oxidation in the fresh oil-free breads but had no effect during gastro-intestinal digestion. The impact of vegetables on macronutrient oxidation in the oil-free breads during digestion appears to be vegetable-specific with broccoli exacerbating it and the others having no effect. Of the evaluated vegetables, beetroot showed the most promising nutritional and physico-chemical benefits when incorporated into bread that does not contain added oil.

Breads Fortified with Freeze-Dried Vegetables: Quality and Nutritional Attributes. Part 1: Breads Containing Oil as an Ingredient

There is increasing emphasis on reformulating processed foods to make them healthier. This study for the first time comprehensively investigated the effects of fortifying bread (containing oil as an ingredient) with freeze-dried vegetables on its nutritional and physico-chemical attributes. Breads fortified with carrot, tomato, beetroot or broccoli were assessed for nutrition, antioxidant potential, storage life, shelf stability, textural changes and macronutrient oxidation. Furthermore, using an in vitro model the study for the first time examined the impact of vegetable addition on the oxidative stability of macronutrients during human gastro-intestinal digestion. As expected, adding vegetables improved the nutritional and antioxidant properties of bread. Beetroot and broccoli significantly improved bread storage life. None of the vegetables significantly affected bread textural changes during storage compared to the control. Lipid oxidation in fresh bread was significantly reduced by all four types of vegetables whilst protein oxidation was lowered by beetroot, carrot and broccoli. The vegetables demonstrated varying effects on macronutrient oxidation during gastro-intestinal digestion. Beetroot consistently showed positive effects suggesting its addition to bread could be particularly beneficial.

Evaluation of Antioxidant Activity, Total Flavonoids, Tannins and Phenolic Compounds in Psychotria Leaf Extracts

The antioxidant activity of Psychotria carthagenensis, P. leiocarpa, P. capillacea and P. deflexa (Rubiaceae) extracts were investigated, and the concentrations of total phenolics, flavonoids, condensed tannins and flavonols were determined. The chemical compositions of the extracts were investigated using the high performance liquid chromatography (HPLC/PAD) method. We used 1,1-diphenyl-1-picrylhydrazyl free radical (DPPH), β-Carotene bleaching and 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cations to determine antioxidant activity. The ability to scavenge radical was measured in these experiments by the discoloration of the solution. Concentrations of constituents were measured spectrophotometrically. P. carthagenensis and P. capillacea exhibited the highest antioxidant activity, in the DPPH test, β-carotene bleaching and ABTS system. The highest phenolic, flavonoid, condensed tannin and flavonol concentration was found in P. carthagenensis and P. capillacea extracts. HPLC-PDA analysis of P. carthagenensis and P. capillacea revealed hydroxycinnamic acid (p-coumaric acid). This is the first report on the antioxidant properties and constituent analysis of these Psychotria extracts.

Kinetics of apple polyphenol diffusion in solutions with different osmotic strengths

Fruits contain polyphenols, widespread antioxidants beneficial for human health. Their mass transfer was studied during the leaching of apple slices immersed in mannitol solutions with ranging concentrations (0, 0.2, 0.4, and 0.6 M). The solution of Fick's law for unsteady mass transfer in planar configuration was used to calculate apparent diffusivity (De). Polyphenols were quantified by high-performance liquid chromatography for each immersion time. Leaching from raw apple tissues occurred only when cell integrity was lost, here at a certain level of difference in osmotic pressure. Different diffusivity values were found in the two apple varieties. Values of De either decreased from 0.2 to 0.1 × 10(-9) and 0.2 × 10(-9) m(2) s(-1) for Golden Delicious and Granny Smith, respectively, or were not determined when the mannitol concentration increased from 0 to 0.6 M. The osmotic strength of the solution strongly impacted the leaching rate of polyphenols from apple cells. The structure of the polyphenols also affected De, with low values for procyanidins.

Study on combined effects of blanching and sonication on different quality parameters of carrot juice

This study was conducted to evaluate the combined effects of blanching and sonication on carrot juice quality. Carrots were blanched at 100 °C for 4 min in normal and acidified water. Juice was extracted and sonicated at 15 °C for 2 min keeping pulse duration 5 s on and 5 s off (70% amplitude level and 20 kHz frequency). No significant effect of blanching and sonication was observed on Brix, pH and titratable acidity except acidified blanching that decreased pH and increased acidity significantly. Peroxidase was inactivated after blanching that also significantly decreased total phenol, flavonoids, tannins, free radical scavenging activity, antioxidant capacity and ascorbic acid and increased cloud and color values. Sonication could improve all these parameters significantly. The present results suggest that combination of blanching and sonication may be employed in food industry to produce high-quality carrot juice with reduced enzyme activity and improved nutrition.

Mango and acerola pulps as antioxidant additives in cassava starch bio-based film

The objective of this study was to investigate the feasibility of incorporating mango and acerola pulps into a biodegradable matrix as a source of polyphenols, carotenoids, and other antioxidant compounds. We also sought to evaluate the efficacy of mango and acerola pulps as antioxidants in film-forming dispersions using a response surface methodology design experiment. The bio-based films were used to pack palm oil (maintained for 45 days of storage) under accelerated oxidation conditions (63% relative humidity and 30 °C) to simulate a storage experiment. The total carotenoid, total polyphenol, and vitamin C contents of films were evaluated, while the total carotenoid, peroxide index, conjugated diene, and hexanal content of the packaged product (palm oil) were also monitored. The same analysis also evaluated palm oil packed in films without antioxidant additives (C1), palm oil packed in low-density polyethylene films (C2), and palm oil with no package (C3) as a control. Although the film-forming procedure affected the antioxidant compounds, the results indicated that antioxidants were effective additives for protecting the packaged product. A lower peroxide index (36.12%), which was significantly different from that of the control (p<0.05), was detected in products packed in film formulations containing high concentration of additives. However, it was found that the high content of vitamin C in acerola pulp acted as a prooxidant agent, which suggests that the use of rich vitamin C pulps should be avoided as additives for films.

The effect of industrial food processing on potentially health-beneficial tomato antioxidants

Increasing desires from both consumers and producers to understand better which nutritive components are present in our food and how these are influenced by industrial processing strategies is resulting in extra research involving the use of state-of-the-art technologies to generate novel biochemical information. In this review, attention has been focused on tomato as this is a product eaten right across the world both as fresh produce and after having been processed in a wide variety of ways. There is a particular interest in tomato as it is a major component in the so-called "Mediterranean diet" which has recently been associated with a healthier lifestyle. Tomatoes are rich sources of a variety of nutritional compounds and especially some key antioxidant components such as the carotenoid lycopene, vitamin C, and a range of polyphenols. The potentially protective properties of these antioxidants are of great interest and the consumer has already become aware of their potential importance. Surveying the literature has revealed that much research has been done on the biochemical composition of tomato and its products. However, it remains difficult to make clear conclusions on optimizing the processing strategy. Many, apparently conflicting, findings have been reported and consequently, in this review, we have drawn attention to these and have attempted to clarify their cause. Finally, a range of recommendations has been made as to how future research might be performed in order to generate more concrete conclusions enabling recommendations towards more optimized processing strategies.

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.

Degradation kinetics of peroxidase enzyme, phenolic content, and physical and sensorial characteristics in broccoli (Brassica oleracea L. ssp. Italica) during blanching

The effects of water blanching treatment on peroxidase inactivation, total phenolic content, color parameters [-a*/b* and hue (h degrees*)], texture (maximum shear force), and sensory attributes (color and texture, evaluated by a trained panel) of broccoli (Brassica oleracea L. ssp. Italica) were studied at five temperatures (70, 75, 80, 85, and 90 degrees C). Experimental results showed that all studied broccoli quality parameters suffered significative changes due to blanching treatments. The vegetal total phenolic content showed a marked decline. Degradation on objective color and texture measurements and alterations in sensorial attributes were detected. Correlations between sensory and instrumental measurements have been found. Under the conditions 70 degrees C and 6.5 min or 90 degrees C and 0.4 min, 90% of the initial peroxidase activity was reduced. At these conditions, no significant alterations were detected by panelists, and a small amount of phenolic content was lost (ca. 16 and 10%, respectively). The peroxidase inactivation and phenolic content degradation were found to follow first-order reaction models. The zero-order reaction model showed a good fit to the broccoli color (-a*/b* and h degrees*), texture, and sensory parameters changes. The temperature effect was well-described by the Arrhenius law.

Effect of the degree of processing on soy oil conjugated linoleic acid yields

Photoirradiation processing can be used to rapidly synthesize conjugated linoleic acid (CLA) in large quantities in soy oil. The objective of this study was to evaluate the effect of the level of refining of soy oil on CLA yields and oxidative properties after photoirradiation. Crude, alkali-refined, alkali-refined bleached, and alkali-refined bleached and deodorized (RBD) soy oils were photoirradiated in a pilot-plant processing system for 12 h with 0.35% iodine catalyst at 47 degrees C. RBD soy oil gave the highest total CLA yield of 16.3% of total oil with 4.3% cis, trans- and trans, cis-CLA isomers. Oxidative stability as measured by weight gain during incubation at 64 degrees C showed that iodine decreased the induction time of soy oil samples by 2-4 days. Photoirradiation processing further decreased the induction time by 2 days as a result of loss of total tocopherols. Iodine addition increased the titratable acidity in all the samples of soy oil. However, the level of refining affects this increase of titratable acidity, and RBD soy oil was found to be the most stable. The study indicates that RBD soy oil was the most suitable candidate for photoirradiation processing. Thus, soy oil should be alkali-refined, bleached, deodorized, and then photoprocessed followed by a secondary adsorption step to remove the iodine catalyst to obtain a RBD CLA-rich soy oil.