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.     

Effect of lyophilisation,refrigerated storage and frozen storage on the coagulant activity and microbiological quality of Cynara cardunculus L. extracts

BACKGROUND: Cheese‐makers have traditionally kept vegetable coagulants refrigerated until use, even though little was known of their microbiological quality or coagulant activity during storage. This study aimed to assess the efficacy of lyophilisation, refrigerated storage and frozen storage of fresh vegetable extract as a means of standardising coagulant activity in terms of coagulation times, pH and microbiological quality. RESULTS: Neither the pH nor the coagulation time of lyophilised extracts was significantly modified during 1 year; however, changes were observed following frozen storage, and more notable following refrigerated storage. Lyophilisation of aqueous extracts prompted the destruction of most micro‐organisms; low counts initially noted for total mesophiles, lactic acid bacteria and yeasts disappeared during the first few days of storage, due to low water activity. There was a generalised decrease in micro‐organism counts during frozen storage. Refrigeration was found to be unsuitable for storing of cardoon extract; an increase of roughly 2 log unit counts was recorded in total mesophile, lactic acid bacteria, yeast and mould counts after 1 year of refrigerated storage. CONCLUSION: Refrigerated storage cannot be considered a suitable method for prolonged conservation of aqueous cardoon extract. Both lyophilisation and frozen storage of aqueous extracts proved ideal for prolonged storage of vegetable coagulant. Lyophilisation additionally had certain advantages over frozen storage. Copyright © 2008 Society of Chemical Industry     

Characterization of Crude Esterase Activity from Two Plants Used in Cheese Making: Cynara cardunculus L. and Ficus carica L.

For centuries, extracts of Cynara cardunculus and the latex of Ficus carica have been used in cheesemaking, thanks to their proteases that clot milk casein. Since esterase activity is important to release odorous compounds in cheese, in this study we characterized the esterase activity of an extract of Cynara cardunculus and the latex of Ficus carica. The results, obtained by titration, spectrophotometric techniques, zymograms, and tests on agar plates, show the presence of esterase activity in the samples tested, with affinity towards the esters of short chain fatty acids, such as acetic, propionic, and butyric acid. In conclusion, this study provides a background information on esterases of two plants used in cheesemaking and represents a starting point for further investigations of their applications, not only in dairying but also in other industries involved in the processing and transformation of lipids.     

Effect of starter cultures on the physico‐chemical and biochemical features in ewe cheese made with extracts from flowers of Cynara cardunculus L

The effect of starter cultures on the physico‐chemical and biochemical features of Los Pedroches cheese made by using Cynara Cardunculus L extracts as vegetable coagulant was assessed. Specimens of cheese containing no starter (vats A and C) and others to which a lactic acid starter was added (vats B and D) were stored either under typical farmhouse ripening conditions (vats A and B) or in a controlled chamber at 14°C and 80% relative humidity (vats C and D) for 90 days. The addition of starter cultures and the ripening conditions where found to have no appreciable effect on the moisture, fat, protein, ash, NaCl, Ca and P contents of the cheese, nor on its water activity; however, it resulted in increased lactic acid contents and lower pH values relative to control specimens throughout ripening. The protein breakdown of the cheeses was assessed in terms of soluble nitrogen, non‐protein nitrogen, aminoacid nitrogen, ammonia nitrogen, soluble tyrosine and tryptophan, and urea‐PAGE. Proteolysis was generally more marked and rapid in cheese containing the lactic starter, the NPN, NH₃ ‐N and soluble Tyr and Trp contents of which were significantly higher than those of the cheese obtained with no starter. The PAGE technique revealed no appreciable differences between the four cheese batches studied; however, it showed the cheese to be more resistant to β‐CN hydrolysis than to α_s‐CN hydrolysis. In general, the flavour and aroma scores were higher in batches obtained with starter cultures and ripened under controlled conditions. © 1999 Society of Chemical Industry     

Evolution of free fatty acid profile during ripening in cheeses manufactured from bovine, ovine and caprine milks with extracts of Cynara cardunculus as coagulant

 Changes in the concentrations of free fatty acids (FFA) in bovine, ovine and caprine milk cheeses manufactured with a plant rennet (flowers of Cynara cardunculus) were studied throughout a 68-day ripening period. The long-chain saturated (C16 : 0 and C18 : 0) and unsaturated (C18 : 1, C18 : 2, and C18 : 3) FFA were the most abundant at all stages of ripening. The overall concentration of FFA in fresh cheese was 3598, 3538 and 3868 mg/kg cheese for bovine, ovine and caprine milk cheeses, respectively; these values increased to 5047, 6517 and 5257 mg/kg cheese, respectively, by 68 days, of which 1171, 1734 and 1791 mg/kg cheese, respectively, were accounted for by C4 : 0 – C12 : 0. The FFA that showed the highest fractional increase by 68 days of ripening in bovine milk cheese were C4 : 0, C6 : 0, C8 : 0, C12 : 0, C18 : 1 and C18 : 2; in ovine milk cheese they were C4 : 0, C6 : 0, C8 : 0, C10 : 0, C14 : 0, and C18 : 1; and in caprine milk cheese they were C4 : 0, C8 : 0, C10 : 0, C14 : 0 and C18 : 1. Received: 2 August 1996     

Cauliflower (Brassica oleracea L), globe artichoke (Cynara scolymus) and chicory witloof (Cichorium intybus) processing by-products as sources of dietary fibre

By-products arising from vegetable processing activities have been assessed in relation to their potential application as sources of dietary fibre supplements in refined foods. Sources used were fresh cauliflower, globe artichoke and chicory witloof. Non-starch polysaccharide (NSP) content and composition of selected parts of each plant source have been measured from alcohol insoluble residues (AIR) and by fibre analysis, complemented by methylation analysis to characterise structural features of component polysaccharides. Results indicate that cauliflower upper stem NSP was similar to the floret (∽25 g kg⁻¹ fresh weight) and each was rich in pectic polysaccharides. Cauliflower lower stem was enriched in NSP (∽66 g kg⁻¹) due mainly to cellulose and xylan deposition, which resulted in a proportionate decrease in pectic polysaccharides. Artichoke stem (∽38 g NSP kg⁻¹) was similar to the receptacle (∽34 g NSP kg⁻¹) but bracts were heavily lignified. Chicory root and leaf bud were each rich in pectic polysaccharides but NSP content was much higher in the root (∽46 g kg⁻¹) than the leaf (∽8 g kg⁻¹). Results indicate that processing by-products, eg cauliflower upper stem, artichoke stem and chicory root, could prove useful as sources of pectic polysaccharide-rich supplements. However, polysaccharide composition and glycosidic linkage pattern also identified important structural differences between sources. The importance of ‘fibre type’ when considering development of food supplements is discussed. © 1998 SCI.     

膜分离技术分离纯化朝鲜蓟叶中洋蓟素的工艺研究

研究了膜技术分离纯化朝鲜蓟叶中洋蓟素的工艺过程,在超滤过程中,采用膜通量及洋蓟素浓度为考察指标。结果表明,10万Da分子量规格的膜为最佳选择,具有较大的膜通透性,产品洋蓟素的截留率低(1.79%)。在产品的纳滤过程,考察膜的透水通量、待测溶液纳滤前后的电导率及洋蓟素浓度指标。结果显示,选用合适的纳滤膜(300Da),浓缩效果好,洋蓟素的产品浓度提高到原液的34.9倍,同时浓缩液中电导率只为普通热真空浓缩的1/10左右。研究结果表明,膜分离技术在本实验研究中应用效果显著,适于进一步的推广应用。     

檀香叶提取物的急性和亚急性毒性研究

目的研究檀香叶提取物的急性毒性和亚急性毒性,对其食用安全性进行评价。方法将昆明小鼠按性别体重随机分组,采用灌胃法,用檀香叶水提取物、95%乙醇提取物进行小鼠急性毒性实验,分别一次灌胃给药37 g/kg体重、38 g/kg体重,观察7 d,测量小鼠体重,脏器质量,并对肝脏和肾脏进行组织切片。用檀香叶醇提物进行小鼠亚急性毒性实验,1日1次灌胃给药25 g/kg体重,持续7 d,观察15 d,测量小鼠体重,脏器质量,并对肝脏和肾脏进行组织切片。结果 :(1)实验结束后,实验组和对照组小白鼠都无死亡;(2)宰杀的实验组小白鼠的各脏器无明显肉眼可见剖检病变;(3)实验组小白鼠的各脏器系数与对照组的差异不显著(P>0.1),组织病理检查未见异常。结论在本实验条件下,按急性毒性分类,檀香叶提取物属无毒级,檀香叶提取物未见明显的亚急性毒性。     

檀香叶提取物抗氧化及抗菌活性初步研究

研究檀香(Sandalwood)叶不同溶剂提取物的抗氧化及抗菌活性,为檀香叶资源开发利用提供依据。采用4种不同溶剂提取檀香叶中抗氧化、抗菌活性成分;采用清除DPPH自由基方法测定抗氧化活性,采用平板打孔法测定抗菌活性。结果表明:檀香叶80%乙醇、水、乙酸乙酯提取物可以清除DPPH自由基;80%乙醇提取物对大肠杆菌、金黄色葡萄球菌、枯草芽孢杆菌有抗菌作用,但对霉菌、啤酒酵母没有抑菌作用。乙醇提取物经不同温度、不同光照时间处理后,其抗氧化、抗菌活性较稳定。乙醇提取物经不同pH处理后,抗氧化物质在pH6～8范围内稳定,抗菌物质在pH3～7范围内稳定,碱性条件下不稳定。檀香叶乙醇提取物化学成分标识结果表明:檀香叶乙醇提取物中含有多糖、鞣质、黄酮类、酚类物、有机酸以及氨基酸、多肽、蛋白质等成分。结论:80%乙醇、水、乙酸乙酯提取物具有抗氧化活性,其中,80%乙醇提取物抗氧化活性最好。只有80%乙醇提取物具有抗菌活性。     

Effect of chlorophyll removal and particle size upon the nutritional and technological properties of powdered by‐products from artichoke (Cynara scolymus,L.) industrial canning

In this study, the effect of the particle‐size fractionation (Ø < 0.212 mm and 0.212 mm < Ø < 0.991 mm) and chlorophyll extraction on the nutritional and technological properties of the powdered artichoke ingredient was evaluated. The contents of minerals, protein, fat, carbohydrates and dietary fibre together with the content in bioactive compounds such as inulin and phenolics were determined. Other properties such as water‐ and oil‐holding capacities, water activity and antioxidant capacity were measured. The ingredient with chlorophyll and the lowest particle size presented the highest phenolic content and antioxidant capacity (8.4 mg of vitamin C equivalents per 100 g of dry matter) and water‐ and oil‐holding capacities. The removal of chlorophyll increased the oil‐holding capacity (from 59.7% to 94.6%), which was much higher than in the coarse ingredient (34%), but has a deleterious effect reducing the antioxidant capacity and the inulin content. The ingredients also showed high dietary fibre (22.5–33%), inulin (9–16%) and mineral (7.5–7.8%) contents. Although the ingredient with chlorophyll and smaller particle size had the higher antioxidant capacity, the removal of chlorophyll improved the technological properties to be used as food ingredient without affecting significantly to the nutritional value.     

Physicochemical characteristics of inulins obtained from Jerusalem artichoke (Helianthus tuberosus L.)

The physicochemical characteristics (thermal stability, glass transition temperature and degree of crystallinity) of inulins, obtained from the tubers of four varieties Jerusalem artichoke (Helianthus tuberosus L.) grown in Bulgaria—Energina, Verona, Topstar and Spindel, were investigated. The inulins obtained had molecular weight from 4,882 to 5,600 Da (degree of polymerization around 30 fructose units). The experimental data from differential scanning calorimetry showed that the glass transition temperature of inulins is between 51 °C and 55 °C. It was found that the first transition (due to evaporation of the unbound water) starts from 77 to 80 °C. The second transition phase started between 152 and 158 °C, and it determines the limit of inulin thermal stability. The data from differential thermal analysis confirmed the results of differential scanning calorimetry with slight differences in the starting temperatures and durations of the phase transitions. X-ray analysis showed that the degree of crystallinity of inulins is very low (except for Spindel inulin—21%).     

The antioxidant properties of alcoholic extracts from Sambucus nigra L. (antioxidant properties of extracts)

The antioxidant properties of alcoholic extracts from the leaves, berries and flowers of Sambucus nigra L. are estimated by means of DPPH and β-carotene/linoleic acid methods, and considered in relation to the extraction temperature (in the range 20-200 °C) and to the level of flavonoids most representative for this plant. The extracts of S. nigra act as antioxidants neutralizing the activities of free radicals and inhibiting the co-oxidation reactions of linoleic acid and β-carotene. There is no direct correlation between the level of flavonoids in the extracts and their antioxidant activity. The data presented show that the extraction temperature strongly influences the antioxidant properties of the extracts, especially in the case of leaves.     

芹菜叶中黄酮类化合物的提取分离与鉴定

芹菜叶经乙醇回流提取后,采用大孔树脂(XDA-1)、聚酰胺树脂和葡聚糖凝胶(Sephadex LH-20)色谱柱分离纯化得到黄酮化合物单体.经1H-NMR,13C-NMR,HMBC,MS,UV等方法鉴定,3个芹菜黄酮单体化合物分别为芹菜素、芹菜苷、3'-甲氧基芹菜苷.     

Free radical scavenging, cytotoxic, and hemolytic activities of an active antioxidant compound ethyl gallate from leaves of Acacia nilotica (L.) Wild. Ex. Delile subsp. indica (Benth.) Brenan

Abstract: In the present study, free radical scavenging, cytotoxic, and hemolytic activities of the polyphenolic compound ethyl gallate isolated from ethanol extract of Acacia nilotica Wild. Ex. Del. leaves were determined. The free radical‐scavenging activities of the ethyl gallate were demonstrated in several in vitro assays in order to evaluate the possible antioxidant mechanism. The results revealed ethyl gallate as hydrogen donor, metal chelator, and free radical scavenger. Ethyl gallate was effective in scavenging 1,1‐Diphenyl‐2‐picrylhydrazyl (DPPH) radicals and the IC₅₀ value was lower than all the positive controls used in this study. Deoxyribose degradation assay revealed that ethyl gallate had more iron‐chelating ability than the direct hydroxyl radical‐scavenging ability. The results of the cytotoxic study revealed that the compound was moderately active and IC₅₀ value was found to be >100 μg/mL for Vero cell lines and 72 μg/mL for Hela cell lines. The compound possessed no hemolytic activity against rat and human erythrocytes revealing its cytotoxic mechanism and nontoxicity. The results from this work will provide an important information for the food and pharmacological industries with respect to the use of the compound as an antioxidant and a health‐related drug. Practical Application: Antioxidant from plant sources is safe to use, as compared to synthetic products. It also can be used as a supplement to alleviate most of the diseases because of its free radical‐scavenging activity.     

Influence of the technological properties of vegetable rennet (Cynara cardunculus) on the physicochemical,sensory and rheological characteristics of ‘Torta del Casar’ cheese

The purpose of this work was to investigate the influence of technological properties of vegetable rennet (Cynara cardunculus) on the characteristics of ‘Torta del Casar’ cheese to establish the parameters that can be useful for quality control of this coagulant. The physicochemical, microbial, texture and sensory properties of the cheeses were evaluated and correlated to clotting and proteolytic activities of the vegetable rennets used for their manufacture. The level of in vitro degradation of α‐casein and κ‐casein/β‐casein degradation ratio was found to be good tools to predict the effect of vegetable rennet on the rheological properties of these cheeses.     

Antioxidant potentials and rosmarinic acid levels of the methanolic extracts of Salvia verticillata (L.) subsp. verticillata and S. verticillata (L.) subsp. amasiaca (Freyn & Bornm.) Bornm

This study was designed to examine the in vitro antioxidant activities and rosmarinic acid levels of the methanol extracts of Salvia verticillata subsp. verticillata and S. verticillata subsp. amasiaca. The extracts were screened for their possible antioxidant activity by two complementary test systems, namely DPPH free radical-scavenging and β-carotene/linoleic acid systems. In the first case, S. verticillata subsp. verticillata was superior to the subsp. amasiaca with an IC₅₀ value of 14.5 ± 1.21 μg mg⁻¹. In the β-carotene/linoleic acid test system, inhibition capacity of S. verticillata subsp. verticillata was 74.4 ± 1.29%. Antioxidant activities of BHT, ascorbic acid, curcumin and α-tocopherol were determined in parallel experiments. Activity of rosmarinic acid was also screened for better establishing the relationship between rosmarinic acid level and antioxidant activity for the plant extracts. S. verticillata subsp. verticillata had the highest rosmarinic acid level with a value of 28.7 ± 0.89 μg mg⁻¹. There is a strong correlation between the rosmarinic acid level and antioxidant activity potential. Our results showed that rosmarinic acid and its derivatives are more likely to be responsible for most of the observed antioxidant activities of Salvia species.