Effect of nano-silica coating combined with pressurized Ar treatment on postharvest quality and reactive oxygen species metabolism in sweet cherry fruit.

The mechanisms of effect of nano-silica coating and pressurized Ar on regulating reactive oxygen species (ROS) generation and scavenging in the senescence of sweet cherries remains unclear. The amounts of reactive oxygen species, hydrogen peroxide, non-enzymatic antioxidants and antioxidases, and cell membrane lipid peroxidation in sweet cherries were determined. Nano-silica coating, pressurized Ar, and the combination of these two treatments, all significantly delayed senescence by suppressing decay rate, and maintained good sensory quality. In additional, all treatments inhibited the generation and accumulation of superoxide anion and hydrogen peroxide, and mitigated the lipid peroxidation of cell membranes of sweet cherries. The combination of these two treatments maintained higher contents of ascorbic acid and glutathione, and enhanced the activities of antioxidases in sweet cherries. It is suggested that nano-silica coating and pressure Ar mediated the ROS metabolism, which might have a role in retaining the quality sweet cherries during cold storage.

A comprehensive review on innovative and advanced stabilization approaches of anthocyanin by modifying structure and controlling environmental factors.

Anthocyanins are pigments abundant in fruits and vegetables, and commonly applied in foods due to attractive colour and health-promoting benefits. However, instability of anthocyanins leads to their easy degradation, reduced bioactivity, and colour fading in food processing, limiting their application and causing economic losses. Stability of anthocyanins depends on their own structures and environmental factors. For structural factors, modification including copigmentation, acylation and biosynthesis is a potential solution to increase anthocyanin stability due to forming stable structures. With regard to environmental factors, encapsulation such as microencapsulation, liposome and nanoparticles has been shown effectively to enhance the stability. We proposed the potential challenges and perspectives for the diversification of anthocyanin-rich products for food application, particularly, introduction of hazards, technical limitations, interaction with other ingredients in food system and exploration of pyranoanthocyanins. The integrated strategies are warranted for improving anthocyanin stabilization for promoting their further application in food industry.

Hypocholesterolemic Effects of Expeller-Pressed and Solvent-Extracted Fruit Seed Oils and Defatted Pomegranate Seed Meals.

Consumptions of fruit seed oils and meals could potentially improve cardiovascular health by reducing plasma total cholesterol and low-density lipoprotein (LDL). The study objective was to compare the effectiveness of expeller-pressed and solvent-extracted grape, tomato, pomegranate seed oils, and defatted pomegranate meals in lowering plasma and hepatic cholesterol using hamster models. Hamsters were fed with fruit seed oils (FSO), defatted pomegranate seed meals (PDM), or control diets. After a 3-week feeding period, plasma total triglycerides of treatment diets were significantly lower. FSO also reduced total, very-low-density lipoprotein- (VLDL), and LDL-cholesterols, while PDM only lowered VLDL-cholesterols. Decreases in low-density and high-density lipoproteins (LDL/HDL) ratios were also observed in most treatments. In liver, triglycerides, total, and free cholesterol levels did not vary between control and treatments. There were no significant differences in lipid modulating properties between solvent-extracted and expeller-pressed oils. In conclusion, partial replacements of saturated fat in high-fat diets with tomato, pomegranate, and grape seed oils could effectively reduce plasma triglyceride levels and improve HDL/LDL ratios.

Effects of infrared radiation combined with heating on grape seeds and oil quality.

The objective of this work was to determine the effects of infrared radiation combined with heating on grape seeds and oil quality. Experimental results showed that high moisture removal was achieved through infrared radiation heating. After infrared radiation heating for 108 s, the inactivation rates of total aerobic bacterial and total mold-yeast counts of the grape seeds were 1.97 ± 0.12 and 0.62 ± 0.09 log CFU/g, respectively. The maximum microbial reduction was achieved after infrared radiation heating of the grape seeds to 135 ℃ and subsequent holding at 75 ℃ for 60 min. The crude oil yield of samples subjected to these conditions was 10.39%, which was significantly higher ( p < 0.05) than that of the control sample, and their final moisture content was 7.20%. Additionally, increases in the free fatty acid content and peroxide value of the oil were achieved. The iodine value of the oil decreased. In conclusion, surface pasteurization with a high oil yield could be achieved by the combination of infrared radiation heating and the holding process. Consequently, infrared radiation treatment is suggested to be a promising method for the surface pasteurization of grape seeds.

Phenolic composition of pomegranate peel extracts using an liquid chromatography-mass spectrometry approach with silica hydride columns.

The peels of different pomegranate cultivars (Molla Nepes, Parfianka, Purple Heart, Wonderful and Vkunsyi) were compared in terms of phenolic composition and total phenolics. Analyses were performed on two silica hydride based stationary phases: phenyl and undecanoic acid columns. Quantitation was accomplished by developing a liquid chromatography with mass spectrometry approach for separating different phenolic analytes, initially in the form of reference standards and then with pomegranate extracts. The high-performance liquid chromatography columns used in the separations had the ability to retain a wide polarity range of phenolic analytes, as well as offering beneficial secondary selectivity mechanisms for resolving the isobaric compounds, catechin and epicatechin. The Vkunsyi peel extract had the highest concentration of phenolics (as determined by liquid chromatography with mass spectrometry) and was the only cultivar to contain the important compound punicalagin. The liquid chromatography with mass spectrometry data were compared to the standard total phenolics content as determined by using the Folin-Ciocalteu assay.

Drying and decontamination of raw pistachios with sequential infrared drying, tempering and hot air drying.

Pistachio nuts have been associated with outbreaks of foodborne disease and the industry has been impacted by numerous product recalls due to contamination with Salmonella enterica. The current hot air drying of pistachios has low energy efficiency and drying rates, and also does not guarantee the microbial safety of products. In the study described herein, dehulled and water-sorted pistachios with a moisture content (MC) of 38.14% (wet basis) were dried in a sequential infrared and hot air (SIRHA) drier to <9% MC. The decontamination efficacy was assessed by inoculating pistachios with Enterococcus faecium, a surrogate of Salmonella enterica used for quality control in the almond industry. Drying with IR alone saved 105min (34.4%) of drying time compared with hot air drying. SIRHA drying of pistachios for 2h with infrared (IR) heat followed by tempering at a product temperature of 70°C for 2h and then by hot air drying shortened the drying time by 40min (9.1%) compared with drying by hot air only. This SIRHA method also reduced the E. faecium cell population by 6.1-logCFU/g kernel and 5.41-logCFU/g shell of pistachios. The free fatty acid contents of SIRHA dried pistachios were on par with that of hot air dried samples. Despite significant differences in peroxide values (PV) of pistachio kernels dried with the SIRHA method compared with hot air drying at 70°C, the PV were within the permissible limit of 5Meq/kg for edible oils. Our findings demonstrate the efficacy of SIRHA drying in achieving simultaneous drying and decontamination of pistachios.

Effect of foxtail millet protein hydrolysates on lowering blood pressure in spontaneously hypertensive rats.

PURPOSE: The objective of this study was to determine the effect of foxtail millet protein hydrolysates on lowering blood pressure in spontaneously hypertensive rats (SHRs). METHODS: The protein of foxtail millet after extruding or fermenting and the raw foxtail millet was extracted and hydrolyzed by digestive protease to generate angiotensin-converting enzyme (ACE) inhibitory peptides. The potential antihypertensive effect of protein hydrolysates from foxtail millet in SHRs was investigated. RESULTS: After 4 weeks of treatment with 200 mg peptides/kg of body weight of protein hydrolysates, blood pressure was lowered significantly, and the raw and extruded samples were more effective than the fermented samples. The serum ACE activity and angiotensin II levels in the treatment groups were significantly lower than that of the control. The percent heart weight decreased in the treatment groups. CONCLUSION: Thus, ingestion of foxtail millet protein hydrolysates especially for the raw and extruded hydrolysates may ameliorate hypertension and alleviate related cardiovascular diseases.

Rice industrial processing worldwide and impact on macro- and micronutrient content, stability, and retention.

Various processing methods are used in the food industry worldwide to produce numerous rice products with desirable sensory qualities based on cultural and cooking preferences and nutritional considerations. The processes result in variable degrees of macro- and micronutrient content, stability, and retention, depending on rice variety and original nutritional quality. In this article, modern and traditional premilling, milling, and postmilling processing methods of different rice types are comprehensively reviewed. The implications of industrial rice processing methods, especially milling, as well as techniques for nutrient extraction, transfer, and enhancement, such as rice parboiling, sprouting, and fortification, for macro- and micronutrient content and consumer acceptance of the products, are documented. Socioeconomic constraints facing various aspects of rice processing methods are also discussed. This article reviews up-to-date research on rice industrial processing worldwide and aims to benefit engineers dealing with food processing, nutritionists and dieticians, food companies, education and research institutions, and quality-control and safety managers.

Thermal stability of liquid antioxidative extracts from pomegranate peel.

BACKGROUND: Liquid extracts from pomegranate peel have the potential for use as natural antioxidant products. This study investigates the quality changes of liquid extracts before and after thermal treatment during sterilization and storage. Liquid pomegranate peel extracts were prepared, sterilized under ultra-high temperature (UHT) at 121 °C for 10 s and then stored at three temperatures (4, 25 and 37 °C) for up to 180 days. The industrial, color, UV-visible spectrum profile and antioxidant (phenolics) characteristics were measured. RESULTS: Thermal sterilization treatment had no negative effects on the industrial, color, spectral and antioxidant characteristics of the extracts. After 180 days, the extracts stored at 4 °C retained 67% of the initial total soluble phenolic content and 58% of the original scavenging activity. The major antioxidant components in the extracts (stored at 4 °C for 180 days) were gallic acid, punicalagin A, punicalagin B and ellagic acid having concentrations of 19.3, 197.2, 221.1 and 92.4 mg L⁻¹, respectively. CONCLUSION: The results show that liquid pomegranate peel extracts had acceptable thermal stability after sterilization and storage. The recommended storage condition of this product was low temperature.

Plasma and hepatic cholesterol-lowering effects of tomato pomace, tomato seed oil and defatted tomato seed in hamsters fed with high-fat diets.

The cholesterol-lowering effects of tomato pomace (TP), tomato seed oil (TSO) and defatted tomato seed (DTS) were determined in male Golden Syrian hamsters. Hamsters fed high-fat diets containing 10% TSO or 18% DTS were compared to a diet containing 10% corn oil and 10% microcrystalline cellulose (control 1), 42% TP were compared to 25% microcrystalline cellulose (control 2). TP, TSO and DTS reduced hepatic total cholesterol (TC) content. DTS also lowered plasma TC and low-density lipoprotein cholesterol (LDL-C) concentrations. Fecal excretion of lipid, bile acid and cholesterol increased in the DTS group compared to control 1. DTS-fed hamsters had higher levels of hepatic CYP7A1, CYP51, ABCB11, and ABCG5 gene expression than control, suggesting both hepatic bile acid and cholesterol synthesis increased due to increased fecal excretion of bile acid and cholesterol. The results suggest that protein, dietary fibre or phenolic compounds in DTS may be responsible for plasma cholesterol decrease.

Study of optimal extraction conditions for achieving high yield and antioxidant activity of tomato seed oil.

UNLABELLED: Value of tomato seed has not been fully recognized. The objectives of this research were to establish suitable processing conditions for extracting oil from tomato seed by using solvent, determine the impact of processing conditions on yield and antioxidant activity of extracted oil, and elucidate kinetics of the oil extraction process. Four processing parameters, including time, temperature, solvent-to-solid ratio and particle size were studied. A second order model was established to describe the oil extraction process. Based on the results, increasing temperature, solvent-to-solid ratio, and extraction time increased oil yield. In contrast, larger particle size reduced the oil yield. The recommended oil extraction conditions were 8 min of extraction time at temperature of 25 °C, solvent-to-solids ratio of 5/1 (v/w) and particle size of 0.38 mm, which gave oil yield of 20.32% with recovery rate of 78.56%. The DPPH scavenging activity of extracted oil was not significantly affected by the extraction parameters. The inhibitory concentration (IC(50) ) of tomato seed oil was 8.67 mg/mL which was notably low compared to most vegetable oils. A 2nd order model successfully described the kinetics of tomato oil extraction process and parameters of extraction kinetics including initial extraction rate (h), equilibrium concentration of oil (C(s) ), and the extraction rate constant (k) could be precisely predicted with R(2) of at least 0.957. PRACTICAL APPLICATION: The study revealed that tomato seed which is typically treated as a low value byproduct of tomato processing has great potential in producing oil with high antioxidant capability. The impact of processing conditions including time, temperature, solvent-to-solid ratio and particle size on yield, and antioxidant activity of extracted tomato seed oil are reported. Optimal conditions and models which describe the extraction process are recommended. The information is vital for determining the extraction processing conditions for industrial production of high quality tomato seed oil.

Storage stability of sterilized liquid extracts from pomegranate peel.

UNLABELLED: Pomegranate marc, a byproduct of commercial juice production, has shown promise as a starting material for the recovery of health promoting phenolic compounds. The stability of aqueous extracts prepared from pomegranate marc was evaluated in preparation to directly using these extracts as nutraceuticals or food additives. The liquid extracts were produced under extraction conditions of 25 °C, water to peel ratio of 50 : 1 (w/w) for 2 min, and then sterilized at 121 °C for 10 s. Storage conditions tested included 3 different pH values (3.5, 5.0, and 7.0) and 2 packaging methods (no light and exposure to light). The extracts were evaluated for industrial (pH, total soluble solid content, and clarity), color, spectral, and antioxidant characteristics over a period of 180 d. The results showed that both pH value and packaging method significantly influenced the industrial and color characteristics of the extracts. The high pH had a negative effect on spectral and antioxidant characteristics. Therefore, the recommended storage conditions are low pH and with dark packaging to maintain the high storage stability. After 180 d of storage, extracts stored at low pH (3.5) in dark packaging still retained 67% and 58% of their total soluble phenolic concentration and antioxidant activity, compared with 61% and 43% for high pH (7.0) samples, and were composed of high concentrations of punicalagins A and B, gallic, and ellagic acids. PRACTICAL APPLICATION: The present research developed an effective recovery of phenolic compounds from pomegranate marc to be used as nutraceuticals or food additives. The aqueous extract product has good quality characteristics with high industrial and color stability, and total phenolic content and antioxidant activity, when stored at pH 3.5 in dark packaging for up to 180 d. The evaluation results of storage stability reported here are important for commercialization.

Continuous and pulsed ultrasound-assisted extractions of antioxidants from pomegranate peel.

There is a great demand for developing efficient extraction methods in order to reduce extraction time and increase the yield and activity of functional antioxidants. The yields, activities, and extraction kinetics of antioxidants from dry peel of pomegranate marc were studied using ultrasound-assisted extraction in continuous and pulsed modes and the results were compared with conventional extraction (CE) at a temperature of 25±2°C and water/peel ratio of 50/1, w/w. The studied factors were intensity level and treatment time for continuous ultrasound-assisted extraction (CUAE), and intensity level, number of pulse repetition, and pulse duration and interval for pulsed ultrasound-assisted extraction (PUAE). The results showed that all factors significantly affected the antioxidant yield, but only treatment time had a significant effect on the antioxidant activity. Compared to CE, PUAE at intensity level of 59.2 W/cm(2), and the 5 and 5s of pulse duration and interval increased the antioxidant yield by 22% and reduced the extraction time by 87%. Similarly, CUAE at the same intensity level increased the antioxidant yield by 24% and reduced the extraction time by 90%. Since PUAE had 50% energy saving compared to CUAE, we recommend using PUAE for the extraction with antioxidant yield of 14.5% and DPPH scavenging activity of 5.8 g/g. A second-order kinetic model was successfully developed for describing the mechanism of ultrasound-assisted extractions under PUAE and CUAE. This research clearly demonstrated the superiority of PUAE for producing antioxidants from peel of pomegranate marc.