Thinned stone fruits are a source of polyphenols and antioxidant compounds.

BACKGROUND: Thinned fruits are agricultural by-products that contain large quantities of interesting compounds due to their early maturity stage. In this work, the phenolic profile and the antioxidant activity of six thinned stone fruits (apricot, cherry, flat peach, peach, plum and nectarine) have been investigated, focussing on proanthocyanidins. RESULTS: Thinned nectarine had the highest content of total phenols [67.43 mg gallic acid equivalents (GAE) g-1 dry weight (DW)] and total flavonoids (56.97 mg CE g-1 DW) as well as the highest antioxidant activity measured by DPPH scavenging (133.30 mg [Trolox equivalents (TE) g-1 DW] and FRAP assay (30.42 mg TE g-1 DW). Proanthocyanidins were very abundant in these by-products, and the main phenolic group quantified in cherry (10.54 mg g-1 DW), flat peach (33.47 mg g-1 DW) and nectarine (59.89 mg g-1 DW), while hydroxycinnamic acids predominate in apricot, peach and plum (6.67, 22.04 and 23.75 mg g-1 DW, respectively). The low, mean degree of polymerisation of proanthocyanidins suggests that their bioavailability could be very high. CONCLUSIONS: This study shows that thinned stone fruit extracts might be used as antioxidants in foods or as a source of compounds with health-related benefits that can be used in the pharmaceutical, cosmetic and food industries. © 2016 Society of Chemical Industry.

Antimicrobial activity of pomegranate peel extracts as affected by cultivar.

BACKGROUND: Some studies have reported that different parts of the pomegranate fruit, especially the peel, may act as potential antimicrobial agents and thus might be proposed as a safe natural alternative to synthetic antimicrobial agents. The high tannin content, especially punicalagin, found in pomegranate extracts, has been reported as the main compound responsible for such antimicrobial activity. Because the pomegranate peel chemical composition may vary with the type of cultivar (sweet, sour-sweet and sour), pomegranates may also differ with respect to their antimicrobial capacity. RESULTS: The extract from PTO8 pomegranate cultivar peel had the highest antimicrobial activity, as well as the highest punicalagins (α and ß) and ellagic acid concentrations. In the results obtained from both antibacterial and antifungal activity studies, the sour-sweet pomegranate cultivar PTO8 showed the best antimicrobial activity, and the highest ellagic acid concentrations. CONCLUSION: The results of the present study suggest that ellagic acid content has a significant influence on the antimicrobial activity of the pomegranate extracts investigated. The pomegranate peel of the PTO8 cultivar is a good source of antifungal and antibacterial compounds, and may represent an alternative to antimicrobial agents of synthetic origin. © 2016 Society of Chemical Industry.

Chemical components from the haulm of Artemisia selengensis and the inhibitory effect on glycation of ß-lactoglobulin.

Artemisia selengensis (AS) has been traditionally used as both food and medicine for thousands of years in China. In our studies, l-tryptophan was first isolated from the haulm of AS together with luteolin, rutin, and kaempferol-3-O-glucuronide. Their structures were elucidated by spectroscopic methods including HRMS, 1D and 2D NMR. Three flavonoid compounds showed satisfactory suppression effects on the formation of advanced glycation end products (AGEs) in ß-lactoglobulin-lactose/MGO/GO model systems, and their anti-glycation activities exhibited a dose-dependent manner. Among these compounds, kaempferol-3-O-glucuronide was demonstrated to be the strongest inhibitor against the formation of AGEs.

The Maillard reaction of a shrimp by-product protein hydrolysate: chemical changes and inhibiting effects of reactive oxygen species in human HepG2 cells.

Recently, much attention has been given to improving the antioxidant activity of protein hydrolysates via the Maillard reaction, but little is known about the cellular antioxidant activity of Maillard reaction products (MRPs) from protein hydrolysates. We first investigated chemical characterization and the cellular antioxidant activity of MRPs in a shrimp (Litopenaeus vannamei) by-product protein hydrolysate (SBH)-glucose system at 110 °C for up to 10 h of heating. Solutions of SBH and glucose were also heated alone as controls. The Maillard reaction greatly resulted in the increase of hydroxymethylfurfural (HMF) and browning intensity, high molecular weight fraction, and reduction of the total amino acid in SBH with the heating time, which correlated well with the free radical scavenging activity of MRPs. MRPs had stronger inhibiting effects on oxidative stress of human HepG2 cells than the original SBH, and its cellular antioxidant activity strongly correlated with free radical scavenging activity, but less affected by the browning intensity and HMF level. The caramelization of glucose partially affected the HMF level and free radical scavenging activity of MRPs, but it was not related to the cellular antioxidant activity. The cellular antioxidant activity of MRPs for 5 h of heating time appeared to reach a maximum level, which was mainly due to carbonyl ammonia condensation reaction. In conclusion, the Maillard reaction is a potential method to increase the cellular antioxidant activity of a shrimp by-product protein hydrolysate, but the higher HMF levels and the lower amino acid content in MRPs should also be considered.

Bats and zoonotic viruses: can we confidently link bats with emerging deadly viruses?

An increasingly asked question is 'can we confidently link bats with emerging viruses?'. No, or not yet, is the qualified answer based on the evidence available. Although more than 200 viruses - some of them deadly zoonotic viruses - have been isolated from or otherwise detected in bats, the supposed connections between bats, bat viruses and human diseases have been raised more on speculation than on evidence supporting their direct or indirect roles in the epidemiology of diseases (except for rabies). However, we are convinced that the evidence points in that direction and that at some point it will be proved that bats are competent hosts for at least a few zoonotic viruses. In this review, we cover aspects of bat biology, ecology and evolution that might be relevant in medical investigations and we provide a historical synthesis of some disease outbreaks causally linked to bats. We provide evolutionary-based hypotheses to tentatively explain the viral transmission route through mammalian intermediate hosts and to explain the geographic concentration of most outbreaks, but both are no more than speculations that still require formal assessment.

Antioxidant effcacy of unripe banana (Musa acuminata Colla) peel extracts in sunflower oil during accelerated storage.

BACKGROUND: Sunflower oil is prone to oxidation during storage time, leading to production of toxic compounds that might affect human health. Synthetic antioxidants are used to prevent lipid oxidation. Spreading interest in the replacement of synthetic food antioxidants by natural ones has fostered research on fruit and vegetables for new antioxidants. METHODS: In this study, the efficacy of unripe banana peel extracts (100, 200 and 300 ppm)  in stabilizing sunflower oil was tested under accelerated storage (65°C) for a period of 24 days. BHA and α-tocopherol served as comparative standards besides the control. Established parameters such as peroxide value (PV), iodine value (IV), p-anisidine value (p-AnV), total oxidation value (TOTOX), thiobarbituric acid reactive substances (TBARS) and free fatty acid (FFA) content were used to assess the extent of oil deterioration. RESULTS: After 24 days storage at 65°C, sunflower oil containing 200 and 300 ppm extract of unripe banana peel showed significantly lower PV and TOTOX compared to BHA and α-tocopherol. TBARS, p-AnV and FFA values of sunflower oil containing 200 and 300 ppm of unripe banana peel extract exhibited comparable inhibitory effects with BHA. Unripe banana peel extract at 200 and 300 ppm demonstrated inhibitory effect against both primary and secondary oxidation up to 24 days under accelerated storage conditions. CONCLUSIONS: Unripe banana peel extract may be used as a potential source of natural antioxidants in the application of food industry to suppress lipid oxidation.

Which is the best grape seed additive for frankfurters: extract, oil or flour?

BACKGROUND: Grape seed products (winery by-products) are valuable vegetable sources to enhance the quality of meat products. In this study, 21 treatments of frankfurters, in three different groups, including 0%, 0.01%, 0.03%, 0.05%, 0.1%, 0.3% and 0.5% grape seed extract (GSE), 0%, 1%, 2%, 4%, 6%, 8% and 10% grape seed oil (GSO), and 0%, 0.5%, 1%, 2%, 3%, 4% and 5% grape seed flour (GSF) were produced in order to compare the differences among them during refrigerated storage for 90 days. RESULTS: Increasing the level of GSO made the frankfurters lighter in color (P < 0.05). Lipid oxidation of all the 21 frankfurters were under the limit of deterioration (2.0 mg malonaldehite kg⁻¹ treatment) during 90 days' storage. However, increasing the amount of additives (GSE, GSO and GSF) led to a decrease in overall acceptability for each group. According to the general comparison of the three frankfurter groups in terms of lipid oxidation, TBARS (thiobarbituric acid reactive substances) values of the frankfurters including GSE and GSF were found to be similar, but the frankfurters containing GSO exhibited the highest lipid oxidation (P < 0.05). While the products including GSE were the most acceptable group in terms of overall acceptability, the group produced with GSF received the lowest points (P < 0.05). CONCLUSION: Although the three grape seed products have partially undesirable effects on the sensory characteristics of the frankfurters, all these additives showed different positive influences in the production of frankfurters. The results showed that the group of frankfurters including GSE was the best of three different groups of products due to the lipid oxidation and overall acceptability results.

Fatty acid composition, physicochemical properties, antioxidant and cytotoxic activity of apple seed oil obtained from apple pomace.

BACKGROUND: Apple pomace is generated in huge quantities in juice-processing industries the world over and continuous efforts are being made for its inclusive utilization. In this study, apple seeds separated from industrial pomace were used for extraction of oil. The fatty acid composition, physicochemical and antioxidant as well as in vitro anticancer properties of extracted oil were studied to assess its suitability in food and therapeutic applications. RESULTS: The fatty acid composition of seed oil revealed the dominance of oleic (46.50%) and linoleic acid (43.81%). It had high iodine (121.8 g I 100 g⁻¹) and saponification value (184.91 mg KOH g⁻¹ oil). The acid value, refractive index and relative density were 4.28 mg KOH g⁻¹, 1.47 and 0.97 mg mL⁻¹, respectively. The antioxidant potential (IC50) of apple seed oil was 40.06 µg mL⁻¹. Cytotoxicity of apple seed oil against CHOK1, SiHa and A549 cancer cell lines ranged between 0.5 ± 0.06% and 88.6 ± 0.3%. CONCLUSION: The physicochemical properties of apple seed oil were comparable with edible food oil, indicating its better stability and broad application in the food and pharmaceutical industries. Apple seed oil could be a good source of natural antioxidants. Also, the in vitro cytotoxic activity against specific cell lines exhibited its potential as an anticancer agent.

Literature review on production process to obtain extra virgin olive oil enriched in bioactive compounds. Potential use of byproducts as alternative sources of polyphenols.

This review describes the olive oil production process to obtain extra virgin olive oil (EVOO) enriched in polyphenol and byproducts generated as sources of antioxidants. EVOO is obtained exclusively by mechanical and physical processes including collecting, washing, and crushing of olives, malaxation of olive paste, centrifugation, storage, and filtration. The effect of each step is discussed to minimize losses of polyphenols from large quantities of wastes. Phenolic compounds including phenolic acids, alcohols, secoiridoids, lignans, and flavonoids are characterized in olive oil mill wastewater, olive pomace, storage byproducts, and filter cake. Different industrial pilot plant processes are developed to recover phenolic compounds from olive oil byproducts with antioxidant and bioactive properties. The technological information compiled in this review will help olive oil producers to improve EVOO quality and establish new processes to obtain valuable extracts enriched in polyphenols from byproducts with food ingredient applications.

Oxidative stability of virgin olive oil as affected by the bene unsaponifiable matters and tertiary-butylhydroquinone.

During 16 h heating at 180 °C, the oxidative stability (OS) of virgin olive oil (VOO) as affected by the same concentrations (200 ppm) of tertiary-butylhydroquinone (TBHQ) and unsaponifiable matters of bene kernel (UKO) and hull (UHO) oils in terms of the inhibitory effect on the formation of conjugated diene hydroperoxides (OS(CDV)) and off-flavor carbonyl compounds (OS(CV)) was investigated. TBHQ was not able to considerably increase the OS(CDV) (7.51) of the VOO (7.2) and showed no synergistic effect with indigenous antioxidative compounds of the VOO (IOV) in this respect. However, it could significantly improve the OS(CV) (from 2.49 to 4.52), which was mainly due to its synergism with the IOV. The UKO increased considerably the OS(CDV) (to 11.8), and its OS(CV) (4.22) was nearly the same as that of TBHQ. The IOV still had marked contributions to the prevention of VOO oxidation but the majority of stabilizing effect was related to the UKO and its synergism with the IOV. The OS(CDV) in presence of the UHO was less than that of the VOO (5.96), although it significantly increased the OS(CV) (to 5.2), mainly due to the stabilizing effect of UHO and its synergism with the IOV.

Application of proanthocyanidins from peanut skins as a natural yeast inhibitory agent.

UNLABELLED: Proanthocyanidins were extracted from peanut skins and investigated for their antimicrobial activity against Saccharomyces cerevisiae, Zygosaccharomyces bailii, and Zygosaccharomyces bisporus in traditional growth media (Sabouraud Dextrose and Maltose broth) and a simulated apple juice beverage. Peanut skins extracts (PSE) were prepared through a multisolvent extraction procedure. The PSE extended the lag phase growth of the 3 yeasts studied at a concentration of 1 mg/mL and at 10 mg/mL yeast growth was totally inhibited for 120 h. PSE was fractionated by normal phase high performance liquid chromatography and the active components/fractions were determined. Compounds present in the fractions were identified by liquid chromatography-mass spectrometry to determine the compounds responsible for inhibition. Fractions consisting mostly of A-type proanthocyanidin dimers, trimers, and tetramers showed the highest percent inhibition toward the yeasts tested in this study. Both optical density (OD) and standard enumeration plating methods were performed in this study. The OD method led to an overestimation of the inhibitory effects of PSE, the 2 methods agreed in respect to treatment effects but not the severity of the inhibition. PRACTICAL APPLICATION: There is a growing consumer demand for "fresh like" products containing reduced amounts of chemical preservatives without compromising food safety and quality. Therefore, the goal of this study was to determine if an extract of peanut skins containing flavonoid rich compounds could function as a natural antimicrobial in a model beverage system. Proteins were removed through the process of producing the peanut skin extract, thus it is unlikely to contain peanut allergens. The antimicrobial compounds mentioned in this study were successfully integrated into a model beverage system, and were found to have antimicrobial effect. However, the incorporation of these compounds would likely lead to negative sensory attributes at the concentration needed to achieve an appreciable antimicrobial effect alone.

Antimicrobial activity of Chinese bayberry extract for the preservation of surimi.

BACKGROUND: Chemical preservatives such as sodium nitrite and potassium sorbate have been widely used to keep surimi products fresh. However, the potential harmfulness to human health cannot be ignored. This study was conducted to develop natural preservatives for the storage of Collichthys surimi. RESULTS: Among the eight Chinese traditional herbs and fruits, Chinese bayberry extract showed the greatest inhibitory effect against surimi spoilage bacteria Serratia marcescens and Pseudomonas aeruginosa. Moreover, N-butanol phase extract of bayberry (NB) showed the greatest activity among the different phases of bayberry extract. When Chinese bayberry extract was combined with tea polyphenol, an additive inhibitory effect was observed on growth of Hansenula anomala, Micrococcus luteus, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli. Our results further indicated that the shelf life of surimi products stored at room temperature can be extended when supplemented with Chinese bayberry extract. CONCLUSION: Our results suggest that Chinese bayberry extract can be used as a natural preservative for the storage of Collichthys surimi.

Activity of citrus essential oils against Escherichia coli O157:H7 and Salmonella spp. and effects on beef subprimal cuts under refrigeration.

UNLABELLED: Escherichia coli O157:H7 and Salmonella spp. are bacterial pathogens often associated with beef, and cause many cases of foodborne illness each year in the United States. During beef slaughter and processing, these bacteria may spread from the hide or intestines to the carcass. The objective of this research was to investigate the use of naturally occurring compounds citrus essential oils (CEOs) extracted from orange peel to reduce or eliminate these pathogens at the chilling stage of processing, or during fabrication. Brisket flats (used to simulate beef subprimals) were spot inoculated with approximately 6 log of surrogate generic E. coli cocktail (previously shown to be identical in growth and survival parameters to E. coli O157:H7 and Salmonella spp.). Following drying, CEOs were applied by spraying at concentrations of 3% and 6% to the surface of different pieces of meat. Treatments were applied using a custom built spray cabinet at 2.07 bar and applied at a rate of 3.79 L/min to replicate commercial practices. The CEOs significantly reduced (P < 0.05) the concentration of E. coli on the brisket flats in comparison to inoculated no spray or water sprayed controls over a period of 90 d, while causing an initial reduction of approximately 1.4 log units. Total aerobic bacteria and psychrotrophic counts were also reduced on uninoculated briskets following treatment. These results indicate that 3% cold-pressed terpeneless Valencia orange oil could be used as an additional intervention against E. coli O157:H7 and Salmonella spp. at the refrigerated storage stage of processing. PRACTICAL APPLICATION: CEOs are natural compounds that have been designated as Generally Recognized as Safe (GRAS). They can be used to control Salmonella spp. and E. coli O157:H7 on beef carcasses at the chilling stage.

High-temperature natural antioxidant improves soy oil for frying.

The objectives of this study were to determine the frying stability of soybean oil (SBO) treated with a natural citric acid-based antioxidant, EPT-OILShield able to withstand high temperatures and to establish the oxidative stability of food fried in the treated oil. Soybean oil with 0.05% and 0.5% EPT-OILShield and an untreated control SBO were used for intermittent batch frying of tortilla chips at 180 degrees C for up to 65 h. Oil frying stability was measured by free fatty acids (FFA) and total polar compounds (TPC). Chips were aged for up to 4 mo at 25 degrees C and evaluated for rancid flavor by a 15-member, trained, experienced analytical sensory panel and for hexanal content as an indicator of oxidation. Oil with 0.05% EPT-OILShield had significantly less FFA and TPC than the control. The effect of EPT-OILShield was apparently retained in aged chips because hexanal levels were significantly lower in chips fried in oil with 0.05% EPT-OILShield than in chips fried in the control. Tortilla chips fried in the control were rancid after 2 mo at 25 degrees C at sampling times evaluated from 25 to 65 h; however, chips fried in oil with 0.05% EPT-OILShield and used for 65 h were described as only slightly rancid after 4 mo. Gamma tocopherol levels were significantly higher in the chips fried in the oil with 0.05% EPT-OILShield than in the control, helping to inhibit oxidation in the tortilla chips during storage.