The effect of storage temperatures on vitamin C and phenolics content of artichoke (Cynara scolymus L.) heads

The effect of temperatures (0, 2, 5, 7 and 10°C) for 14 days of storage on antioxidant constituents such as vitamin C and phenolic compounds of artichoke c.v. ‘Blanca de Tudela’ was studied. Three groups of phenolics were identified and quantified as: chlorogenic acid; 1,5-dicaffeoylquinic acid (1,5 di-CQA)+3,5-dicaffeoylquinic acid (3,5 di-CQA); and 1,4-dicaffeoylquinic acid (1,4-di-CQA)+4,5-dicaffeoylquinic acid (4,5 di-CQA). The content of vitamin C was higher in the internal bracts compared with the external ones (144 and 193 mg kg⁻¹ fresh wt., respectively) and decreased after 14 days of storage under the assayed temperatures. Each individual group of phenolics was 10-fold higher in the internal bracts than in the external ones. At harvest, total phenolics (618 mg kg⁻¹), chlorogenic acid (143 mg kg⁻¹) and 1,4 di-CQA+4,5 di-CQA (207 mg kg⁻¹), increased in internal bracts after storage, particularly at 2, 5 and 7°C. On the other hand, 1,5-di-CQA+3,5-di-CQA decreased from 260 to 150 mg kg⁻¹ after storage. Consumption of the edible artichoke fraction could be an important source of natural antioxidants and provide significant nutritional value to the diet.     

Changes in inulin and soluble sugar concentration in artichokes (Cynara scolymus L.) during storage

BACKGROUND: The artichoke (Cynara scolymus L.) accumulates about 50–70 g kg^?1 of its fresh weight as inulin‐type fructan. Inulin fermentation increases gas production and thereby provokes intestinal discomfort in some people. The present research focuses on the changes in carbohydrate composition occurring in artichoke heads during storage under different conditions (18 °C, 4 °C and 4 °C under polypropylene film packing). RESULTS: Carbohydrate content and composition were determined by anion‐exchange high‐performance liquid chromatography with pulsed amperometric detection. Storage time caused a decrease in inulin content and an average degree of polymerization, accompanied by an increase of free fructose and sucrose due to depolymerization of inulin. CONCLUSION: Higher‐temperature storage and storage without packing induce strong carbohydrate changes. Thereby, eating stored artichoke leads to consumption of an inulin quantity that does not provoke unwanted symptoms related to gas production but sufficient to have a prebiotic effect. Copyright © 2010 Society of Chemical Industry     

Effect of artichoke extract (Cynara scolymus L.) on palmitic-1-14C acid oxidation in rats

Studies on the effect of the artichoke extract (AE) on oxidation of palmitic-1-14C acid administered intravenously to rats at a dose 25 and 50 mg/kg bw demonstrated marked enhancement of both 14CO2 expiration rate and 14CO2 recovery in the expired air. The extract suppressed accumulation of palmitic-1-14C acid in serum lipids and epididymal fat pad tissue as well. The effects of the extract on 14CO2 expiration rate, 14CO2 recovery, as well as accumulation of palmitic-1-14C acid were dose dependent. Total14CO2 recovery in expired air during 60 min was elevated by 17.3% (p < 0.05) and 52.1% (p < 0.001) in rats administered the extract at a dose of 25 and 50 mg/kg, respectively. The rats supplemented with the AE at a dose of 25 and 50 mg/kg bw were characterized by 10.0% (not significant) and 19% (p < 0.05) decrease in( 14)C radioactivity of serum lipids as well as reduction of epididymal fat tissue 14C radioactivity by 8.7 and 17.5% (p < 0.05), respectively, in comparison with the control rats. Thus, the results demonstrate that the AE possess stimulatory properties with respect to oxidation of palmitic acid administered to rats, and provide new information on the mechanism of antilipemic activity of the extract associated with activation of lipid oxidation in the organism.     

In Vivo Genotoxicity Evaluation of an Artichoke (Cynara scolymus L.) Aqueous Extract

The Cynara scolymus (artichoke) is widely consumed as tea or food and shows important therapeutic properties. However, few studies have assessed the possible toxic effects of artichoke extracts. This study evaluates genotoxic and mutagenic activities of artichoke leaf aqueous extract in mice using the comet assay and the micronucleus test. Leaf extracts were given by gavage (500 mg/kg, 1000 mg/kg, and 2000 mg/kg) for 3 consecutive days. Extract composition was investigated using phytochemical screening and high‐performance liquid chromatography (HPLC). In addition, antioxidant capacity was analyzed through the diphenyl‐picrylhydrazyl (DPPH) and xanthine oxidase assay. Phytochemical screening detected the presence of phenolic compounds, flavonoids, and saponins. HPLC analyses indicated the presence of chlorogenic acid, caffeic acid, isoquercetrin, and rutin. Extracts showed a dose‐dependent free radical scavenging effect of DPPH and an inhibitory effect of xanthine oxidase. The genotoxic results showed that leaf extracts did not increase micronuclei in peripheral blood cells. Compared to the control group, a significant increase in comet assay values was observed only in bone marrow of group treated with 2000 mg/kg, the highest dose tested, indicating that artichoke tea should be consumed with moderation. Practical Application: This is the first report of in vivo mutagenic and genotoxic evaluation with C. scolymus. The present study revealed leaf aqueous extract from artichoke shows lack of mutagenicity in vivo, and low genotoxicity and antioxidant activity; indicating that artichoke tea should be consumed with moderation.     

Bioactivity of hydrolysates obtained from bovine casein using artichoke (Cynara scolymus L.) proteases

The objective of this work was to obtain casein hydrolysates with aspartic proteinases present in extracts from the artichoke flower (Cynara scolymus L.) and evaluate their antioxidant, antimicrobial, and angiotensin-I converting enzyme (ACE) inhibitory activity in vitro. The casein hydrolysates produced by the action of C. scolymus had elevated antihypertensive and antioxidant activity due to their high hydrophobic peptide content (93.84, 96.58, and 90.54% at 2, 4, and 16 h of hydrolysis, respectively). Hydrolysis time and molecular weight (<3 kDa) had a significant influence on the hypertensive and antioxidant activity of the hydrolysates, which were greater at hydrolysis times of 4 and 16 h and corresponding to the <3 kDa fractions. The <3 kDa fraction of the 16 h hydrolysate had an ACE inhibitory activity with a half-maximal inhibitory concentration (IC₅₀) of 71.77 µg peptides per mL; DPPH and ABTS^•+ radical scavenging activities of 6.27 µM and 6.21 mM Trolox equivalents per mg of peptides, respectively; and iron (II) chelation activity with an IC₅₀ of 221.49 µg of peptides per mL. Antimicrobial activity against Enterococcus faecalis was also observed in the hydrolysates. From the peptide sequences identified in the hydrolysates, we detected 22 peptides (from the BIOPEP database) that were already in their bioactive form (AMKPWIQPK, AMKPWIQPKTKVIPYVRYL, ARHPHPHLSFM, DAQSAPLRVY, FFVAPFPEVFGK, GPVRGPFPII, KVLPVPQK, LLYQEPVLGPVRGPFPIIV, MAIPPKKNQDK, NLHLPLPLL, PAAVRSPAQILQ, RELEELNVPGEIVESLSSSEESITR, RPKHPIKHQ, RPKHPIKHQGLPQEVLNENLLRF, SDIPNPIGSENSEK, TPVVVPPFLQP, VENLHLPLPLL, VKEAMAPK, VLNENLLR, VYPFPGPIH, VYQHQKAMKPWIQPKTKVIPYVRY, VYQHQKAMKPWIQPKTKVIPYVRYL) and are reported to display antioxidant, antimicrobial, and ACE inhibitory activity. We also identified 12,116, 14,513, and 25,169 peptide sequences in the hydrolysates at 2, 4, and 16 h, respectively, that were contained in the primary sequence, and these are reported to display ACE inhibitory, antioxidant, dipeptidyl peptidase IV inhibition, antithrombotic, opioid, immunomodulation, antiamnesic, anticancer, chelating, and hemolytic bioactivity.     

朝鲜蓟叶水提取物对酒精诱导人肝癌细胞株HepG2损伤的影响

目的通过建立酒精损伤HepG2细胞模型,探讨朝鲜蓟叶水提取物对酒精诱导的HepG2细胞损伤的影响。方法以人肝癌细胞株HpeG2为实验材料,采用酒精加入细胞培养液培养HepG2细胞,建立酒精损伤HepG2细胞模型,以MTT(3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide)法筛选酒精处理浓度、时间以及朝鲜蓟叶水提取物最佳作用浓度,通过检测各组细胞培养基中谷丙转氨酶(alanine aminotran-sferase,ALT)、谷草转氨酶(aspartate transaminase,AST)和细胞内超氧化物歧化酶(superoxide dismutase,SOD)、丙二醛(malondialdehyde,MDA)、甘油三酯(triglyceride,TG)的活性,来评价朝鲜蓟叶水提取物对酒精诱导的HepG2肝细胞损伤的影响。结果分别以0.6%、1.2%、2.4%的酒精浓度联合2.5、5、10μg/mL朝鲜蓟叶水提取物培养HepG2细胞48 h。模型组随着酒精浓度增高,细胞的AST、ALT、TG、MDA水平明显升高,SOD活性显著下降。处理组随着朝鲜蓟叶水提取物使用浓度的增加,细胞中AST、ALT、TG、MDA水平与模型组相比明显下降,SOD活性升高,对HepG2细胞的保护作用增强。结论朝鲜蓟叶水提取物在一定程度上能保护酒精受损的HepG2细胞,具有深入研究和开发的潜能。     

Combined effects of irradiation and modified atmosphere packaging on minimally processed Chinese cabbage (Brassica rapa L.)

Cut Chinese cabbage with air, CO₂ or CO₂/N₂ packaging was irradiated at doses up to 2 kGy and the microbiological and physicochemical qualities were investigated during a refrigerated storage for 3 weeks. Irradiation significantly reduced the microorganisms, and additionally, the modified atmosphere packaging (MAP) enhanced the reduction of the total aerobic and coliform bacteria during storage. Irradiation effectively inhibited the changes of the titratable acidity and pH, while a significant effect was not shown in the texture by irradiation. Antiradical and antioxidant activity, and the phenolic contents were slightly increased by irradiation at 0.5 kGy, while the phenolic contents were reduced by irradiation over 1 kGy. Our results suggest that irradiation at 1 kGy or above can be used to enhance the microbial safety of cut Chinese cabbage without a significant loss in the quality attributes.     

自发气调包装对辣椒贮藏品质的影响

为探究不同自发气调包装对辣椒贮藏品质的影响,以\     

Influence of the modified atmosphere packaging on shelf life and quality of Navalinda sweet cherry

The benefits of different wrap-films for Navalinda sweet cherry, packaged in small-format (consumer packages), were analysed. A storage and distribution process entailing eight days at 4 °C plus four days at 20 °C was simulated. The cherries were packed in punnets and film-wrapped with one macroperforated film and two microperforated films of 0.30 (MAP.30) and 0.55 (MAP.55) µmol cm/cm² atm day of CO₂ permeability at 0 °C. Packing in MAP at 0 °C did not alter the subsequent respiratory intensity of the fruits at 20 °C; however, the respiratory intensity at 20 °C did increase when the storage temperature was raised to 4 °C. The concentration of CO₂ (%) inside the packets at 20 °C was proportional to the permeability of the films: MAP.30 (21%) and MAP.55 (15%). The microperforated films preserved fruit acidity and firmness while slowing down the darkening of colour, loss of quality and decay. Shelf life was most effectively prolonged with MAP.30 film. However, in view of the levels of hypoxia reached at 20 °C, its use is recommended only in the distribution and marketing processes with failsafe cold chains. The recommendations of use of the films, for the different markets, are expressed in light of the obtained results.     

Effect of germination on vitamin C,phenolic compounds and antioxidant activity in flaxseed (Linum usitatissimum L.)

Flaxseed (Linum usitatissimum L.) is well known for its health benefits and chemical composition. This study aimed to evaluate the dynamic changes caused by germination in vitamin C, phenolic compounds and antioxidant activities of flaxseed. It was observed that eight‐day germination of flaxseed sprouts caused increases in phytochemical contents, that is 22.1‐fold increase in vitamin C, 2.67‐fold increase in phenolics and 5.48‐fold increase in flavonoid contents as compare to initial concentration in flaxseeds on dry weight basis. The stimulation was also noted in the three identified phenolic acid ingredients including caffeic acid, p‐coumaric acid and ferulic acid. Similarly, the total PSC and ORAC values of flax sprouts at day 8 increased by 3‐ to 4‐folds compared to nongerminated flaxseeds. It is revealed that comparatively, 8‐day germination of flax sprouts leads to a significant increase in vitamin C, phenolic constituents and total antioxidant activities than those of flaxseeds.     

Antimicrobial Activities of Cynara scolymus L. Leaf, Head, and Stem Extracts

ABSTRACT: Successive chloroform, ethanol, and ethyl acetate partitions of extracts from Cynara scolymus L. leaf, head, and stem were tested for their antimicrobial activity against 15 microbial species, including 7 foodborne bacterial pathogens, Bacillus subtilis, Staphylococcus aureus, Agrobacterium tumefaciens, Micrococcus luteus, Escherichia coli, Salmonella typhimurium , and Pseudomonas aeruginosa , 4 yeasts, Candida albicans, Candida lusitaniae, Saccharomyces cerevisiae , and Saccharomyces carlsbergensis , and 4 molds, Aspergillus niger, Penicillium oxalicum, Mucor mucedo , and Cladosporium cucumerinum using the disk diffusion assay technique. The leaf extract was found to be most effective against all of the tested organisms, followed by the head and stem extracts, and the ethanol fraction showed the most significant antimicrobial activity against all of the tests among 3 soluble fractions of extract, followed by the chloroform and ethyl acetate fractions. The minimum inhibitory concentrations (MICs) of extracts determined by the agar and broth dilution method ranged from 1.25 to 10.0 mg/mL. The MIC of ethanol fraction of leaf extracts was the lowest by comparison with the other 2 extracts. The MIC for fungi was at or below 2.5 mg/mL and for bacteria was at or above 2.5 mg/mL.     

Optimisation of inulin extraction from globe artichoke (Cynara cardunculus L. subsp. scolymus (L.) Hegi.) by electromagnetic induction heating process

In this study, a D‐optimal design was used to optimise the extraction process conditions of inulin with a high degree of polymerisation from Globe artichoke heart (Cynara cardunculus L. subsp. scolymus (L.) Hegi.), using electromagnetic induction heating (EMIH) as a new extraction process. Four factors were simultaneously studied which were the extraction temperature (55–90 °C), the extraction time (30–120 min), the weight ratio (plant material dry weight/volume of distilled water: 5–10%) and the mode of heating (conventional or electromagnetic induction heating). It was found that the second‐order polynomial models developed by the response surface methodology (RSM) describe adequately the relationship between the factors and responses (extraction yield, viscosity and solubility of inulin). The optimum extraction conditions that led to a maximal extraction yield (45.98%) and an optimal viscosity (3.25 mL g^?1) of extracted inulin are temperature of 89.49 °C, extraction time of 120 min and a 5.01% of weight ratio using EIMH process. Fourier Transform InfraRed spectroscopy spectrum of the extracted inulin was identical to that of the native inulin. The analysis of the extract by thin‐layer chromatography confirms the absence of pectin in the final product, as well as the X‐ray diffraction analysis exhibits a semi‐crystalline structure of the biopolymer.     

芦笋MA保鲜技术研究

对芦笋一次性充气MA贮藏保鲜进行了研究,结果表明,初始气体浓度比例对失重影响不明显,而对感官评价值、Vc含量、纤维素含量、叶绿素含量等影响较大。在各种初始气体浓度比例中以5％O_2 5％CO_2和10％O_2 10％CO_2的MA贮藏保鲜效果最好,4℃～5℃下贮藏18d后仍有较好的品质。     

自发气调包装对不同品种青椒贮藏品质的影响

目的 探究自发气调包装对不同品种青椒贮藏品质的影响。方法 以贵州主栽的“改良螺丝椒王”和“黔椒8号”品种为实验材料,使用MP20气调包装袋对其进行包装处理,贮藏于(10±0.3)℃的环境内32d,每隔8 d进行一次相关指标的测定,研究贮藏期间不同品种间青椒品质变化。结果 随着贮藏时间的延长,青椒果实的腐败率、失重率和转红指数均呈上升趋势,相比之下,“黔椒8号”的贮藏性能优于“改良螺丝椒王”。两个品种共检测出48种挥发性物质,主要以醛类、酯类为主;在贮藏末期,“黔椒8号”对醛类和酯类物质的保留率高于“改良螺丝椒王”,风味损失较少。根据化合物的香气活性值得出,两个辣椒品种共有的关键特征呈香物质为:(E,E)-2,4-癸二烯醛、水杨酸甲酯、肉豆蔻醛、正己醛、2-己烯醛和β-紫罗兰酮,其含量均随着贮藏时间的延长而下降。贮藏期间,“改良螺丝椒王”特有的挥发性物质为3-蒈烯和反式-2-壬醛,“黔椒8号”特有的挥发性物质为1-己醇和环己醇。结论 在低温下采用MP20气调包装袋进行包装的“黔椒8号”的贮藏效果最佳。     

气调包装对番石榴贮藏品质的影响

研究12℃时4%O2+5%CO2+91%N2的气调包装对番石榴贮藏品质的影响。与相同温度下未气调包装相比,气调包装能够延缓果实的软化,推迟果肉内过氧化物酶活性和还原糖含量的达峰时间,降低了VC和可滴定酸的分解速率,抑制了丙二醛的生成速率。结果表明,气调包装的番石榴保质期比未气调样品延长了一倍,其在番石榴贮藏保鲜中有一定的推广应用价值。     

Biogenic amine content and biogenic amine quality indices of sardines (Sardina pilchardus) stored in modified atmosphere packaging and vacuum packaging

A comparative study of the effects of packaging on the formation of biogenic amines during storage of sardines (Sardina pilchardus) at 4 °C in air, modified atmosphere pack (MAP) and vacuum pack (VP) was carried out. Sardines were organoleptically acceptable for up to 3 days in air, 12 days in MAP and 9 days in VP. The biogenic amine content generally increased in all treatments with increasing storage time. The concentrations of putrescine and/cadaverine in fish stored in air reached maximum levels of 12.2 mg/100g at 12 days and 10.0 mg/l00 g at 15 days. Significant differences were found (P < 0.05) in the levels of cadaverine and putrescine among the three treatments. Spermidine and spermine levels increased slightly and did not change much throughout the storage period for all experimental conditions. The amine contents of sardine were highest in sardine stored in air, followed by VP and MAP. Quality indices related to the contents of the major biogenic amines were calculated and they correlated well with organoleptic qualities.