Comparison of chlorine and peroxyacetic-based disinfectant to inactivate Feline calicivirus, Murine norovirus and Hepatitis A virus on lettuce

In recent years, raw fruits and vegetables have frequently been involved in foodborne transmission to humans of enteric viruses, particularly noroviruses and hepatitis A virus (HAV). Although viral contamination can occur during all steps of food processing, primary production is a critical stage on which prevention measures must be focused to minimize the risk of infection to consumers. Postharvest sanitation may be a valid technological solution for decreasing the bacterial load on fresh raw material, but there is a lack of data concerning the effectiveness of this process on enteric viruses. In this study, we compared the survival of two human norovirus surrogates, the feline calicivirus (FCV), and the murine norovirus (MNV-1), and of HAV on lettuce after water washing with bubbles and with or without ultrasound, and washing with bubbles in the presence of active chlorine (15 ppm) or peroxyacetic acid-based disinfectant (100 ppm). Cell culture and quantitative RT-PCR assays were used to detect and quantify the viruses on the surface of the lettuce after the sanitizing treatments. Levels of viral inactivation on the lettuce leaves were not significantly different between washing with bubbles and washing with bubbles plus ultrasound and were not dependant on the quantification method. A simple washing without disinfectant resulted in a decrease of approximately 0.7 log units in the quantity of virus detected for HAV and FCV and of 1.0 log unit for MNV-1.In the experimental set-up including a washing step (with or without ultrasound) followed by washing for 2 min in the presence of disinfectants, 15 ppm of active chlorine was found more effective for inactivating FCV (2.9 log units) than HAV and MNV-1 (1.9 log units and 1.4 log units, respectively) whereas 100 ppm of peroxyacetic-based biocide was found effective for inactivating FCV (3.2 log units) and MNV-1 (2.3 log units), but not HAV (0.7 log units). Quantitative RT-PCR results indicated that the presence of viral RNA did not correlate with the presence of infectious viruses on disinfected lettuce, except for MNV-1 processed with chlorine (15 ppm). In comparison with water washing, a substantial additional decrease of genomic FCV titer (1.1 log units) but no significant reduction of the genomic titers of HAV and MNV-1 were found on lettuce treated with chlorine (15 ppm). No significant effect of the disinfection step of lettuce with peroxyacetic-based biocide (100 ppm peracetic acid) was found by qRT-PCR on all genomic viral titers tested. This study illustrates the necessity of determining the effectiveness of technological processes against enteric viruses, using a relevant reference such as HAV, in order to reduce the risk of hepatitis and gastroenteritis by exposure to vegetables.     

The effect of cranberry juice and cranberry proanthocyanidins on the infectivity of human enteric viral surrogates

The effect of cranberry juice (CJ) and cranberry proanthocyanidins (PAC) on the infectivity of human enteric virus surrogates, murine norovirus (MNV-1), feline calicivirus (FCV-F9), MS2(ssRNA) bacteriophage, and phiX-174(ssDNA) bacteriophage was studied. Viruses at high (∼7 log₁₀ PFU/ml) or low (∼5 log₁₀ PFU/ml) titers were mixed with equal volumes of CJ, 0.30, 0.60, and 1.20 mg/ml final PAC concentration, or water and incubated for 1 h at room temperature. Viral infectivity after treatments was evaluated using standardized plaque assays. At low viral titers, FCV-F9 was undetectable after exposure to CJ or the three tested PAC solutions. MNV-1 was reduced by 2.06 log₁₀ PFU/ml with CJ, and 2.63, 2.75, and 2.95 log₁₀ PFU/ml with 0.15, 0.30, and 0.60 mg/ml PAC, respectively. MS2 titers were reduced by 1.14 log₁₀ PFU/ml with CJ, and 0.55, 0.80, and 0.96 log₁₀ PFU/ml with 0.15, 0.30, and 0.60 mg/ml PAC, respectively. ?-X174 titers were reduced by 1.79 log₁₀ PFU/ml with CJ, and 1.95, 3.67, and 4.98 log₁₀ PFU/ml with PAC at 0.15, 0.30, and 0.60 mg/ml, respectively. Experiments using high titers showed similar trends but with decreased effects. CJ and PAC show promise as natural anti-virals that could potentially be exploited for foodborne viral illness treatment and prevention.     

Antiviral effects of cranberry juice and cranberry proanthocyanidins on foodborne viral surrogates – A time dependence study in vitro

Cranberry juice (CJ) and cranberry proanthocyanidins (PAC) are widely known for their antibacterial, antiviral, and pharmacological activities. The effect of CJ and cranberry PAC on the infectivity of foodborne viral surrogates, murine norovirus (MNV-1), feline calicivirus (FCV-F9), MS2 (ssRNA) bacteriophage, and ?X-174 (ssDNA) bacteriophage after 0 min to 1 h at room temperature was evaluated. Viruses at titers of ∼5 log₁₀PFU/ml were mixed with equal volumes of CJ at pH 2.6, CJ at pH 7.0, 0.30 mg/ml CJ PAC, 0.60 mg/ml PAC, or water and incubated for 0, 10, 20, 30, 40, 50 min, and 1 h at room temperature. Infectivity was determined using standard plaque assays. The viral reduction rates of the four tested viruses were found to vary considerably. Among the tested viruses, FCV-F9 titers were decreased the most by ∼5 log₁₀PFU/ml within 30 min. MS2 titers were decreased the least by only ∼1 log₁₀PFU/ml after 1 h with CJ at pH 2.6 and 0.30 mg/ml PAC, and ∼0.5 log₁₀PFU/ml with CJ at pH 7.0 and 0.15 mg/ml PAC. MNV-1 and ?-X174 showed comparable titer reductions which was between that of FCV-F9 and MS2. In most cases, viral reduction within the first 10 min of treatment accounted for ≥50% of the total reduction. Transmission electron microscopy on FCV-F9 treated with CJ and PAC revealed structural changes. This study shows potential of using natural bioactive compounds for controlling foodborne viral diseases. Further studies are necessary to elucidate the mechanism of action of CJ components and to understand the differences in viral titer reduction profiles.     

Grape seed extract as antioxidant in cooked, cold stored turkey meat

Efficiency of four concentrations of grape seed extract (0.0, 0.4, 0.8, and 1.6 g/kg) in retarding oxidative rancidity was tested with cooked turkey breast meat. Development in lipid oxidation during 13 days of refrigerated storage was evaluated by means of thiobarbituric acid-reactive substances (TBARS) and volatile compound formation. Hexanal, pentanal, octanal, 2-octenal, 1-octen-3-ol, 2-octen-1-ol, and 1-penten-3-ol showed high correlations (r>0.95) with TBARS values and could, therefore, serve as markers for the oxidation process in the cooked turkey breast meat. Supplementation of grape seed extract prior to cooking significantly improved oxidative stability of minced turkey meat during heat treatment and storage. The ability of grape seed extract to prevent lipid oxidation was concentration-dependent. Vacuum-packaging considerably improved oxidative stability of meat regardless of the low concentration of grape seed extract used. It appears that grape seed extract could be very effective in inhibiting lipid oxidation of cooked turkey meat during chill-storage.     

Chlorine disinfection of produce to inactivate hepatitis A virus and coliphage MS2

Disinfection of produce is principally used to inactivate spoilage microbes and may also reduce the risk of consumer exposure to enteric pathogens. However, the rate and extent of enteric virus inactivation by free chlorine on produce has not been adequately characterized. Experiments were performed to determine the kinetics of free chlorine inactivation of hepatitis A virus (HAV) and the indicator virus coliphage MS2 on strawberries (SBs), cherry tomatoes (CTs), and head lettuce (HL). The oxidant demand of these produce items also was determined. When produce items were exposed to approximately 20 parts per million (ppm) solution of free chlorine for 5-10 min, HAV and MS2 were inactivated by 90-99% and in some cases virus inactivation was >/=99%. Exposure of strawberries to approximately 200 ppm free chlorine resulted in more rapid and extensive inactivation of both viruses. The produce items tested in this study exhibited a demand for chlorine which varied by produce type, and chlorine residuals declined over time. These results demonstrate the potential for chlorine to reduce the levels of infectious viruses on different produce types, but adequate contact time and chlorine residual are required to achieve maximum virus inactivation. The difference in chlorine demand between SBs, CTs, and HL suggests that varying disinfection practices are needed for the wide variety of processed fruits and vegetables. The inactivation kinetics of MS2 and HAV were similar, suggesting that MS2 and perhaps other similar bacterial viruses may be used as process indicators and surrogates for determining the disinfection efficacy of produce in the laboratory or in actual practice.     

葡萄籽提取物主要质量指标研究

目的 为了确定保健食品原料葡萄籽提取物主要质量指标的参数,本实验搜集30批次葡萄籽提取物并测定了其主要质量指标。方法 采用紫外分光光度法测定了葡萄籽提取物的原花青素值、多酚含量,采用液相色谱法测定了儿茶素、表儿茶素含量,参照食品安全国家标准,测定了灰分、水分、微生物指标(菌落总数、大肠杆菌、沙门氏菌、酵母菌、霉菌)、重金属和溶剂残留等主要质量指标。结果 所有葡萄籽提取物样品中原花青素值范围在81.1%至108.2%之间;儿茶素及表儿茶素含量范围为1.12%至8.58%;多酚含量在70.1%至106.1%之间;灰分含量范围在0.2%至1.8%;水分含量范围在3.76%至5.23%。变异系数由大到小的顺序为：儿茶素、表儿茶素＞灰分＞多酚＞水分＞原花青素值。所有样品菌落总数均小于10 CFU/g,大肠杆菌、沙门氏菌均未检出,酵母菌、霉菌总数均小于10 CFU/g,甲醇、乙醇残留均小于2 mg/kg,重金属(以pb计)小于0.05 mg/kg。结论 与我国目前唯一相关标准对比,所有质量指标中,仅原花青素值的限量需要进一步调整。     

Addition of grape seed extract and bearberry to porcine diets: Influence on quality attributes of raw and cooked pork

The effect of supplementation of pig diets with grape seed extract (GSE) (100, 300, 700 mg/kg feed) and bearberry (BB) (100, 300, 700 mg/kg feed) for 56 days pre-slaughter, on the oxidative stability and quality of raw and cooked M. longissimus dorsi (LD) was examined. Susceptibility of porcine liver, kidney and heart tissue homogenates to iron-induced (1 mM FeSO₄) lipid oxidation was also investigated. In raw LD steaks, stored in modified atmosphere packs (75% O₂:25% CO₂) (MAP) for up to 16 days at 4 °C, surface lightness (CIE ‘L’ value), redness (CIE ‘a’ value), lipid stability (TBARS, mg MDA (malondialdehyde)/kg muscle) and pH were not significantly affected by supplemental GSE or BB. Similarly, the oxidative stability and sensory properties of cooked LD steaks, stored in MAP (70% N₂:30% CO₂), for up to 28 days at 4 °C, were not enhanced by dietary GSE or BB. Iron-induced lipid oxidation increased in liver, kidney and heart tissue homogenates over the 24 h storage period and susceptibility to oxidation followed the order: liver > heart > kidney. Dietary GSE or BB did not significantly reduce lipid oxidation in tissue homogenates. Potential reasons for the lack of efficacy of supplemental GSE and BB on pork quality were explored.     

In vitro study of antioxidant capacity and antibacterial activity on oral anaerobes of a grape seed extract

Grape seeds are considered rich sources of polyphenolic compounds that show antioxidant or antimicrobial effects. The aim of the present work was to investigate the effect of a grape seed extract (GSE) on two oral anaerobes closely associated with periodontal diseases and its antioxidant action.     

The effects of grape seed extract fortification on the antioxidant activity and quality attributes of bread

The antioxidant activity change of breads added with grape seed extract (GSE) was investigated. The results showed that bread with the addition of GSE had stronger antioxidant activity than that of blank bread, and increasing the level of GSE addition further enhanced the antioxidant capacity of the bread. However, thermal processing caused antioxidant activity of GSE added to bread to decrease by around 30–40%. We also studied the effect of GSE on the formation of detrimental N^ε-(carboxymethyl)lysine (CML), a famous advanced glycation endproduct in bread. According to the results, GSE could reduce CML in bread and acted in a dose-dependent manner. Meanwhile, except for an acceptable colour change, adding GSE to bread had only little effect on the quality attributes of the bread. Altogether, our findings indicate that GSE-fortified bread is promising to be developed as a functional food with relatively lower CML-related health risks, yet a high antioxidant activity.     

Grape seed extract inhibits lipid oxidation in muscle from different species during refrigerated and frozen storage and oxidation catalyzed by peroxynitrite and iron/ascorbate in a pyrogallol red model system

The antioxidant effect of grape seed extract (GSE) was determined by assessing the bleaching of pyrogallol red (PGR) by peroxynitrite or iron/ascorbate, and the formation of lipid hydroperoxides (LOOH) and thiobarbituric acid substances (TBARS) in raw or cooked ground muscle during refrigerated or frozen storage. In PGR models, GSE was more effective than gallic acid in inhibiting oxidation. The formation of LOOH and TBARS was inhibited by GSE (0.1% and 1.0%) compared to untreated controls and samples treated with sodium tripolyphosphate. Diethylenetriaminepentaacetic acid (DTPA), alone or in combination with GSE, had no effect on LOOH or TBARS, which provides clues about the possible mechanism of action of GSE. These results show that GSE at concentrations as low as 0.1% is a very effective inhibitor of primary and secondary oxidation products in various muscle systems and has potential as a natural antioxidant in raw and cooked meat systems.     

Effects of grape seed extract on the oxidative and microbial stability of restructured mutton slices

The antioxidant and antimicrobial efficacy of grape seed extract (GSE) was studied in restructured mutton slices (RMS) under aerobic and vacuum packaging conditions during refrigerated storage. The RMS treated with grape seed extract (GSE) had significantly (P < 0.05) lower thiobarbituric acid reactive substance (TBARS) values and free fatty acids (FFA) % compared to control (C) and butylated hydroxy anisole (BHA) treated RMS during storage at 4 ± 1 °C. Addition of GSE significantly (P < 0.05) reduced the total psychrophilic and coliform counts in RMS during refrigerated storage. The GSE treated mutton slices recorded significantly (P < 0.05) superior scores of color, flavor, juiciness and overall palatability than C and BHA treated RMS. The TBARS values, FFA % and microbial counts increased significantly (P < 0.05) during storage. It can be concluded that GSE has excellent antioxidant and antimicrobial properties compared to control and BHA treated RMS during refrigerated storage under aerobic and vacuum conditions.     

葡萄籽提取物对健康人体尿液的代谢组学研究

目的:采用1H-NMR代谢组学技术研究口服葡萄籽提取物后人体尿液中内源性代谢产物的变化规律。方法:选择16名健康男生随机平均分成两组,即试食组（A）和对照组（B）。试食组每人每天口服葡萄籽提取物软胶囊2粒,连续14d,对照组连续服用安慰剂14d。分别收集试食组及对照组服药前（0d）和服药后（14d）的晨尿,运用1H-NMR代谢组学技术分析尿液中内源性代谢产物的变化及其规律。结果:与对照组相比,服药14d后,试食组人体尿液中乳酸水平下降,肌酐水平上升,且具有显著性差异（p<0.05,0.01）;结论:葡萄籽提取物（GSE）对人体尿液中内源性代谢产物的调节作用显著,涉及能量代谢和氨基酸代谢通路,对能量代谢的调节尤为显著,是一种很好的运动营养补充剂。1H-NMR代谢组学技术在运动科学研究中的应用前景广阔。      

Effect of dietary grape seed extract and Cistus ladanifer L. in combination with vegetable oil supplementation on lamb meat quality

Thirty-six Merino Branco lambs were assigned to six dietary treatments: control diet (C) consisting of 90% dehydrated lucerne and 10% wheat bran; C with 6% of oil blend (CO); C with 2.5% of grape seed extract (GS); GS with 6% of oil blend (GSO); C with 25% of Cistus ladanifer (CL), and CL with 6% of oil blend (CLO). Meat lipid and colour stability was then evaluated during 7days of storage. The effect of inclusion of grape seed extract and C. ladanifer in diets on meat sensory properties was also evaluated. Meat antioxidant potential, determined after oxidation induction by a ferrous/hydrogen peroxide system, decreased with oil supplementation (P<0.001), but inclusion of grape seed extract and C. ladanifer in diets protected the meat against lipid oxidation (P=0.036). Meat colour was not affected by diets. Inclusion of grape seed extract and C. ladanifer in diets did not change the sensory properties of meat.     

The effect of grape seed extract or Cistus ladanifer L. on muscle volatile compounds of lambs fed dehydrated lucerne supplemented with oil

Thirty-six Merino Branco lambs were assigned to six dietary treatments: control diet (C) consisting of 90% dehydrated lucerne and 10% wheat bran; control diet with 6% of oil blend (CO); control with 2.5% of grape seed extract (GS); control with 2.5% of grape seed extract and 6% of oil blend (GSO); control with 25% of Cistus ladanifer (an aromatic bush widespread in Portugal; CL); control with 25% of C. ladanifer and 6% of oil blend (CLO). The muscle longissimus dorsi was then subjected to the analysis of volatile compounds (SPME–GC/MS). The CLO diet increased the concentration of heptanal, 3-hydroxy-2-butanone and 2-ethyl-phenol in muscle compared to the CL diet. When lambs received the CL diet, their meat contained lower amounts of 4-heptenal compared to the other treatments. The meat of the GS and GSO lambs contained similar amounts of volatile compounds deriving from lipid oxidation (such as heptanal, 2-nonenal, 4-heptenal and 3-hydroxy-2-butanone). These results indicate that in the presence of grape seed extract, oil supplementation did not enhance the production of lipid-derived volatile compounds. Verbenone and 2,2,6-trimethyl-cyclohexanone were detected only in the meat of the Cistus-fed lambs, suggesting that these compounds could be markers of feeding Cistus-containing diets. Meat volatile compounds profile allowed to discriminate between the lambs receiving C. ladanifer and those not receiving this bush in the diet.     

Antioxidant capacity and inhibitory effect of grape seed and rosemary extract in marinades on the formation of heterocyclic amines in fried beef patties

The effect of oil-based marinades containing grape seed extract (Vitis vinifera L.; 0.2, 0.4, 0.6 and 0.8 g/100 g) formulated in a water/oil emulsion or rosemary extract (Rosmarinus officinalis; 0.12, 0.2, 0.6, 1.0 and 1.5 g/100 g) in oil on the formation of heterocyclic amines (HAs) in fried beef patties was examined. After application of marinades and frying, four HAs MeIQx (2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline), PhIP (2-amino-1-methyl-6-phenylimidazo[4,5b]pyridine), Norharman, and Harman were found at low levels in all fried patties, MeIQx (0.3–1.0 ng/g), and PhIP (0.02–0.3 ng/g). The content of MeIQx and PhIP were significantly reduced by approx. 57% and 90% (p < 0.05), respectively, after use of marinades containing the highest extract concentration. The antioxidant capacity of grape seed was about two-times greater than that of rosemary extract. A correlation between inhibition of HAs and Trolox-equivalents (MeIQx, R² = 0.85, p < 0.001; PhIP, R² = 0.83, p < 0.001) was found. Sensory tests showed a high acceptance of flavour and colour for controls and samples.