真空微波干燥对南瓜片主要类胡萝卜素的影响

利用C30柱及高效液相色谱-二极管阵列检测-大气压化学电离串联质谱方法,对南瓜片中主要类胡萝卜素进行了定性、定量检测,研究了真空微波干燥条件对南瓜片中类胡萝卜素组成及含量的影响。结果表明：真空微波干燥南瓜片总类胡萝卜素含量显著高于热风干燥（P＜0.05）。微波强度对南瓜片中类胡萝卜素的影响最大,其次是真空度和切片厚度。随着微波强度的增加,南瓜片总类胡萝卜素含量显著减少（P＜0.05）,增大真空度和切片厚度在一定程度上提高了干样总类胡萝卜素的含量。与此同时南瓜片中类胡萝卜素主要组分α-、β-胡萝卜素和叶黄素含量随微波强度增加而减少,随真空度和切片厚度增加而增加;而β-胡萝卜素各顺式异构体随真空度增加而减少,但随切片厚度增加含量变化不明显。由此可见,增大真空度和切片厚度有利于提高类胡萝卜素保留率,而高微波强度使类胡萝卜素含量下降。     

Supercritical CO2 Extraction of β-Carotene from Sweet Potatoes

Using supercritical CO₂ to extract β-carotene there was approximately a five-fold or a three-fold increase in amount of carotenoids extracted from freeze-dried tissue relative to the amount extracted from oven-dried or fresh tissue, respectively. The most efficient conditions were at 48°C and 41.4 MPa. Of the total carotenoid content ～20% was inaccessible to supercritical CO₂. The HPLC carotenoid profile of sweet potatoes showed that the unextracted tissue contained 90%β-carotene, primarily as all-trans (ca. 99%). Supercritical CO₂ extracts contained up to 94%β-carotene. The isomer composition of β-carotene of supercritical extracts showed ～ 14% 13-cis and 11% 9-cis.     

Carotenoid Photostability in Raw Spinach and Carrots During Cold Storage

A reverse-phase gradient HPLC method was developed for separating xanthophylls, chlorophylls, carotenes and cisβ-carotene isomers from raw spinach and carrots. The effect of dark and lighted cold storage on pigment stability was studied. Light promoted pigment losses in raw spinach. Degradative losses at 8 days ranged from 60% for violaxanthin to 22% for lutein. Dark, cold storage did not affect carotenoid levels except for all-transβ-carotene which showed an 18% loss at 8 days. In raw carrots, neither lighted nor dark cold storage affected major carotenoids. In spinach, the isomeric distribution of β-carotene showed strong linear correlations between trans and cis forms.     

Characterization and thermal lability of carotenoids and vitamin C of tamarillo fruit (Solanum betaceum Cav.)

The carotenoids from yellow tamarillo were determined by high-performance liquid chromatography-photodiode array detection/mass spectrometry (HPLC-PDA/MS). Xanthophylls were found as esterified with palmitic and myristic acids. All-trans-β-cryptoxanthin esters and all-trans-β-carotene were the major carotenoids of tamarillo. Changes in carotenoid and vitamin C contents after thermal pasteurization of degassed and not degassed tomato tree nectars were studied. Zeaxanthin esters appeared to be the less thermo-labile carotenoids. Carotenoids degradation was not significantly influenced by dissolved oxygen level. However, thermal treatment induced 5,8-epoxidation and cis-isomerization. Retention of ascorbic acid was total under degassed conditions while losses of dehydroascorbic acid were not affected by the initial level of dissolved oxygen.     

Determination of carotenoids in Dunaliella salina cultivated in Taiwan and antioxidant capacity of the algal carotenoid extract

A simple HPLC method with good separation efficiency was developed to determine all-trans and cis forms of carotenoids in Dunaliella salina cultivated in Taiwan. The analysis used a C30 column (250 × 4.6 mm, 5 μm) and an isocratic solvent system (flow rate = 1 mL/min) mixing methanol–acetonitrile–water (84/14/2, v/v/v) and methylene chloride, (75/25, v/v). Carotenoids were detected at 450 nm. Moreover, the antioxidant capacities of the algal carotenoid extract were also evaluated with Trolox equivalent antioxidant capacity (TEAC) assay, reducing power and 2,2-diphenyl-2-picrylhydrazyl hydrate (DPPH) radical scavenging assay. Results showed that 7 carotenoids in the algal extract could be separated simultaneously within 30 min and the total amount of them was 290.77 mg/g algae. The contents of all-trans-β-carotene and 9- or 9′-cis-β-carotene, the major carotenoids in the algae, were 138.25 and 124.65 mg/g algae, respectively. The contents of all-trans-lutein, all-trans-zeaxanthin, 13- or 13′-cis-β-carotene, all-trans-α-carotene and 9- or 9′-cis-α-carotene were 6.55, 11.27, 4.95, 2.69, and 2.41 mg/g algae, respectively. The algal carotenoid extract had significantly higher antioxidant activity than all-trans forms of α-carotene, β-carotene, lutein and zeaxanthin in all antioxidant assays. The cis forms of carotenoids, especially 9- or 9′-cis-β-carotene, might play crucial roles for the antioxidant capacities of the algal extract.     

Analysis of carotenoids with emphasis on 9-cis β-carotene in vegetables and fruits commonly consumed in Israel

Recent epidemiological studies have directed the attention from the synthetic all-trans β-carotene to natural carotenoids predominant in fruits and vegetables as possible active ingredients for prevention of cancer and cardiovascular diseases. Seventeen fruits and 17 vegetables commonly consumed in Israel and the β-car-otene-rich alga, Dunaliella bardawil, were analysed for their content of carotenoids with emphasis on 9-cis β-carotene by reversed-phase, 3D photodiode array HPLC. Fourteen carotenoids were eluted in order of decreasing polarity, from polar oxycarotenoids to lipophilic hydrocarbons, and quantified in μg carotenoid per gram freeze-dried plant sample. The richest sources of total carotenoids (>100μg/g dry weight) in Israeli fruits were pittango, mango and papaya while, in vegetables, the predominant types were carrot, dill, parsley, tomato, lettuce, sweet potato and red pepper. Red fruits and vegetables contained mainly lycopene. Yellow and orange fruits and vegetables had high contents of hydrocarbon carotenes with substantial levels of cryptoxanthins and xanthophylls. The green vegetables had high contents of both xanthophylls and hydrocarbon carotenes. Relatively high ratios (9-cis to all-trans β-carotene) of above 0.2 g/g were noted in sweet potato, papaya, parsley, lettuce, dill, apricot, pepper, prune and pumpkin, compared to the high ratio of 9-cis to all-trans β-carotene in the alga Dunaliella (~ 1.0 g/g). The high content of 9-cis β-carotene in certain fruits and vegetables and the wide variety of carotenoids and stereoisomers of carotenoids in all plants should shift nutritional and medical attention from the synthetic all-trans β-carotene toward natural carotenoids as potential candidates for chemoprevention.     

真空微波干燥中微波强度对胡萝卜和南瓜中类胡萝卜素生物利用率的影响

为明确真空微波干燥过程中,微波强度对胡萝卜和南瓜中类胡萝卜素生物利用率的影响,本文采用静态体外模拟消化模型评价类胡萝卜素生物利用率的变化,采用透射电镜（TEM）和光学显微镜观察细胞壁微观结构的变化。结果表明,真空微波干燥后的胡萝卜和南瓜的细胞壁断裂,有色体结构破坏严重。经体外模拟消化,胡萝卜和南瓜消化液细胞结构破坏明显,细胞壁破裂严重,类胡萝卜素从细胞内部释放到消化液中的含量明显高于鲜样,且类胡萝卜素生物利用率随微波强度的增加呈现先升高后降低的趋势。当微波强度为9 W/g时,胡萝卜和南瓜中类胡萝卜素的生物利用率较高,其β-胡萝卜素生物利用率相比于鲜样分别显著提高了12.02、24.2倍（P<0.05）。由此可知,选择合适的微波强度有助于提高蔬菜中类胡萝卜素生物利用率。     

Ultra-performance liquid chromatographic separation of geometric isomers of carotenoids and antioxidant activities of 20 tomato cultivars and breeding lines

All-trans-lutein, lycopene, β-carotene and their 22 cis-isomers in 20 tomato breeding were separated and identified by a rapid and sensitive UPLC method using a 1.7 μm C₁₈ column and a new gradient mobile phase based on methanol-MTBE-water in 15 min. All-trans-carotenoids were predominant, but 9-cis, 13-cis-lutein, 5-cis, 9-cis, 13-cis, 15-cis, di-cis-lycopene, 9-cis, 13-cis, 15-cis and di-cis-β-carotene were also found. The cis-isomers were identified using absorption around 330 nm and the Q-ratio. The total antioxidant activities as evaluated by PCL and DPPH assays were found to correlate well with the total carotenoid content, but not with the individual carotenoid or its different isomers. This paper provides an efficient analytical method for obtaining a complete picture of carotenoids in tomatoes. It can be a valuable tool for plant breeders, food processors and researchers in developing designer tomatoes and tomato-products with unique carotenoid compositions, and functional properties.     

Effects of supercritical CO2 fluid parameters on chemical composition and yield of carotenoids extracted from pumpkin

Pumpkin is a traditional food that is grown extensively worldwide and is believed to be beneficial to human health due to its high contents of carotenoids. The carotenoids in pumpkin were extracted by organic solvents and by supercritical carbon dioxide (SC-CO₂), and then they were identified, quantified, and compared. β-carotene (31 to 40 g per 100 g of total carotenoids) was the predominate carotenoid in pumpkin. Lutein and lycopene contents were much higher in SC-CO₂ extracts than those in organic solvent extract. Cis-β-carotene increased by more than two times in the SC-CO₂ extracts, even at a relatively low temperature of 40 °C, over those in the solvent extracts, indicating both enhanced solubility and isomerization from trans- to cis-β-carotene. The influences of modifier (10 mL/100 mL), temperature (40-70 °C), and pressure (25-35 MPa) of SC-CO₂ extraction on the change of carotenoid yields were also investigated. The highest yield (109.6 μg/g) was obtained at 70 °C and 35 MPa, with a 73.7% recovery. Selective extraction could be achieved by adjusting the temperature and pressure. Higher proportions of all-trans-β-carotene extracts were achieved at 40 °C under both 25 MPa and 35 MPa conditions. In order to extract more cis-isomers, a higher temperature of 70 °C was preferred.     

南瓜渣的微波真空干燥

加工南瓜汁时得到大量的副产品南瓜渣,南瓜渣富含具有生物活性功能的β-胡萝卜素和膳食纤维,是一种值得开发和利用的保健食品资源。文中采用微波真空干燥,力求最大程度保存β-胡萝卜素。在不同微波功率和压强条件下测定水分含量和β-胡萝卜素含量,得到干燥曲线以及β-胡萝卜素失活曲线。研究结果表明,提高微波功率可以大大提高干燥速度。通过增加压强可以提高干燥速度,但会加快β-胡萝卜素的失活。在668.37W和4 000Pa条件下干燥时,β-胡萝卜素的保留率最高,达到92.31％。通过对3个干燥模型的比较,得出Page模型能较好地描述南瓜渣的微波真空干燥特性。     

Partial purification and characterization of polyphenol oxidase from Chinese parsley (Coriandrum sativum)

Rates of thermal degradation and isomerization of all-trans-β-carotenes in air and in triacylglycerols were determined. Degradation of carotenes in triacylglycerols was faster than that in air. The 13-cis-β-carotene level in triacylglycerols was higher than in air. Oxidized materials of triacylglycerols probably facilitated isomerization of carotenes and, thus, degradation. Amounts of all-trans-β-carotenes and all-trans-α-carotenes in pumpkin decreased with an increase in heating time. The proportion of 13-cis-β-carotene increased after heat treatment started, probably due to thermal isomerization of all-trans-β-carotenes to cis-isomers, and to decreases in amounts of all-trans-β-carotenes and all-trans-α-carotenes in pumpkin. Effects of heating methods on proportions of isomers; however, were not different.     

Degradation and isomerization of chlorophyll a and β-carotene as affected by various heating and illumination treatments

The degradation and isomerization of β-carotene and chlorophyll a as affected by oven-heating, reflux-heating, iodine-catalysed illumination, and non-iodine-catalysed illumination, were studied. Results showed that the degradations of both total β-carotene and chlorophyll a may fit the first-order model under either heating or illumination treatment. 13-cis-β-Carotene and 13,15-di-cis-β-carotene were the major cis isomers of β-carotene formed during oven heating, while 13-cis-β-carotene was favoured during reflux heating. For illumination with or without iodine as catalyst, 13,15-di-cis-β-carotene was the major cis isomer of β-carotene formed. The formation of 13,15-di-cis-β-carotene may be due to conversion of either 13-cis- or 15-cis-β-carotene. No epimerization of chlorophyll a was observed as a result of illumination.     

Suppressive effect of carotenoid extract of Dunaliella salina alga on production of LPS-stimulated pro-inflammatory mediators in RAW264.7 cells via NF-κB and JNK inactivation

The carotenoid extract from Dunaliella salina was used to evaluate the suppressive effects on lipopolysaccharide (LPS)-induced pro-inflammatory mediators in RAW264.7 cells. The extract composed all-trans forms of α-carotene (28.8 mg/g extract), β-carotene (471.1 mg/g extract), lutein (7.1 mg/g extract) and zeaxanthin (7.2 mg/g extract), 13- or 13′-cis-β-carotene (12.1 mg/g extract), 9- or 9′-cis-α-carotene (19.1 mg/g extract) and 9- or 9′-cis-β-carotene (440.3 mg/g extract) dose-dependently reduced the production of interleukin (IL)-1β, IL-6 and tumor necrosis factor-α (TNF-α), the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), and the secretion of nitric oxide (NO) and prostaglandin E₂ (PGE₂) in LPS-activated RAW264.7 cells. Its attenuation of LPS-induced inflammatory responses was closely related to inhibition of the nuclear NF-κB p50 subunit translocation by blocking inhibitor of κBα (IκB) phosphorylation and degradation correlated with suppressing IκB kinase (IKK) α/β phosphorylation, as well as down-regulation of the c-Jun NH₂-terminal kinase (JNK) activation.     

Effects of additional fibrils on structural and rheological properties of rice bran albumin solution and gel

Non-availability of standards is the main problem in quantification of carotenoids from plants. In this regard, six major carotenoids, i.e. all-E-luteoxanthin, 13-Z-lutein, all-E-lutein, all-E-zeaxanthin, 15-Z-β-carotene and all-E-β-carotene, were purified using open-column chromatography and thin-layer chromatography. Using these purified standards, carotenoids from fresh leaves, flowers and fruits of eight commercially grown cultivars of Moringa oleifera were quantified by liquid chromatography–mass spectrometry. All-E-lutein was found as the major carotenoid in leaves and fruits and accounted for 53.6 and 52.0 % of the total carotenoids, respectively. Among the eight cultivars screened, the cultivar Bhagya (KDM-1) had the maximum amount of all-E-zeaxanthin, all-E-β-carotene and total carotenoids. The methodology used in the present investigation for purification and quantification of carotenoids is simplified and hence finds use in screening of carotenoids in other plants. Results also explore the M. oleifera leaves as a rich source of carotenoids, which is significant for its implications in malnutrition programme to alleviate the vitamin A deficiency.     

Degradation compounds of carotenoids formed during heating of a simulated cashew apple juice

The influence of organic acid and heating treatments on carotenoid degradation on a simulated cashew apple juice was assessed by high performance liquid chromatography coupled with a photodiode array and mass spectrometry detectors. A total of nineteen carotenoids were separated in unheated simulated cashew apple juice, with all-trans-β-cryptoxanthin and all-trans-β-carotene as the major ones. As a consequence of heating, five xanthophylls disappeared, whereas two new cis isomers and five epoxide or furanoid-derivatives were formed and the levels of all cis isomers increased. In addition, 12′-apo-β-carotenal was formed at 90 °C. Two oxidation compounds (12′-apo-β-carotenal and 5,6-epoxy-β-cryptoxanthin) were formed after β-cryptoxanthin heating at 90 °C in an aqueous-based system. In all systems, the amounts of total carotenoids lost were not compensated by those formed. These facts indicated that isomerisation and oxidation to both coloured and non-coloured compounds were the main reactions occurring during heating of carotenoids in aqueous-based and juice systems.     

Carotenoids and antioxidant capacities from Canarium odontophyllum Miq. fruit

Carotenoids were isolated and identified from peel, pulp and seed fractions of Canarium odontophyllum Miq., and their antioxidant capacities were evaluated. all-trans-β-carotene was present in a large amount in peel (69.5 ± 1.0 mg/kg), followed by pulp (31.1 ± 0.76 mg/kg) and seed (15.1 ± 3.0 mg/kg). Additionally, 15-cis-β-carotene, 9-cis-β-carotene and 13-cis-β-carotenes were also major contributors to carotenoid contents in peel, pulp and seed fractions. Pulp exhibited excellent β-carotene bleaching activity, significantly higher than peel and seed; high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity, whereas peel exhibited significantly higher scavenging activity of 2,2’-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals. All the extracts exhibited good inhibitory effect against hydrogen peroxide-induced haemoglobin oxidation, ranging from 45.3 to 59.7%. This is the first report about carotenoids and antioxidant capacities from C. odontophyllum fruit, and indicates that this fruit can be explored and promoted as a potential source of natural antioxidants.     

Production of a carotenoid-rich product by alginate entrapment and fluid-bed drying of Dunaliella salina

A new carotenoid-rich product was formed by entrapment of Dunaliella salina in calcium alginate beads of different alginate concentrations, followed by drying in a fluid-bed dryer. The drying process yielded β-carotene recoveries of between 79 and 89% and produced a change in the 9-cis/all-trans ratio of β-carotene isomers. The carotenoid stability of the product was dependant on both the storage conditions and alginate content (range 3·3–7·3 g litre⁻¹) of the beads. In the presence of light and oxygen total carotenoid degraded following a first order kinetic model with degradation constants between 0·016 and 0·039 days⁻¹, with the lowest degradation occurring with the lowest alginate concentration. Product stored in the dark and flushed with nitrogen produced first-order degradation constants of 0·012 and 0·020 days⁻¹ for the two higher alginate concentrations; that with the lowest alginate content showed no noticeable degradation after 58 days storage. During storage, the 9-cis isomer was significantly more unstable showing a relative loss under all conditions, degrading almost completely when stored in the presence of light and oxygen and reaching an equilibrium ratio with the all-trans isomer when stored in the dark and flushed with nitrogen. © 1998 SCI.     

Carotenoid Composition and Vitamin A Value of Fresh and Pasteurized Cashew-Apple (Anacardium occidentale L.) Juice

The carotenoid composition of the red and yellow cashew-apples and two commercial brands of pasteurized juice were determined by column and thin-layer chromatography, visible absorption spectroscopy and specific chemical reactions. Alpha-carotene, β-carotene, ζ-carotene, cis-β-carotene, cryptoxanthin, aurochrome, cryptochrome, and auroxanthin were identified in all samples, with β-carotene as the predominant pigment. Color differences reflected the total amount, not the type of carotenoid present. Geographic effects on the pigment composition did not appear to be appreciable. In the processed juice, the total carotenoid content and vitamin A value were lower but the epoxide level higher. No quantitative differences were noted among lots of the same brand or between brands of pasteurized juice.     

Use of dried pumpkins in wheat bread production

Pumpkins belong to the family of Cucurbitaceae. They are classified to Cucurbita pepo, Cucurbita moschata, Cucurbita maxima and Cucurbita mixta, according to the texture and shape of their stems. The nutritional value of pumpkin fruits is high, varies from one species or cultivar to another. Pumpkins are reach in vitamins C, B₁, B₆, K, and in mineral substances. There are no data found about vacuum microwave dried pumpkin application in wheat bread production. The main purpose of the research was to evaluate quality parameters of microwave vacuum dried pumpkins and to verify its application in wheat bread production. Following quality parameters of pumpkins and bread made with pumpkin additive were evaluated: moisture content (oven – drying method), vitamin C content (iodometric), carotenoid content (spectrophotometric), reducing sugars (LVS 252:2000), colour changes (ColorTec- PCM), total fat content (ISO 6492:1999), degree of bread liking (ISO 4121:2003), bread baking loss and dry off. Quality parameters of non dried pumpkins were: content of reducing sugars − 2.40 g⋅100 g^-1, vitamin C – 0.26 g⋅100 g^-1, carotenoids – 0.50 mg % (in dry matter). The technological parameters for pumpkins drying in vacuum microwave drier were used: pressure (70–50 mmHg), speed of tumbler – 6 rpm, one working cycle and three stages. During the pumpkins drying process a decrease in the following parameters was observed: moisture content – 10.5 times, vitamin C content – 2.0 times; increase of yellowness (b*) value – 1.5 times. The optimal dried pumpkin additive to the wheat dough was 10% of the total flour amount. The wheat bread sample with dried pumpkins additive is richer in carotenoids and reducing sugars comparing to control wheat bread sample. The results of sensory analyses using hedonic rating demonstrated that a higher degree of liking was attributed to the bread sample with dried pumpkins additive (7.3) comparing to control wheat bread sample (6.7).     

好食脉孢霉发酵产类胡萝卜素的鉴定、抗氧化性及稳定性研究

利用液相色谱-质谱联用技术对好食脉孢霉(Neurospora sitophila)固态发酵生产的类胡萝卜素进行初步鉴定,研究了类胡萝卜素粗提物的抗氧化活性和稳定性。N.sitophila来源的类胡萝卜素的主要成分之一为β-胡萝卜素;当质量浓度为6μg/mL时,类胡萝卜素的DPPH自由基清除率显著高于α-生育酚、丁基羟基茴香醚(butyl hydroxylanisole,BHA)和β-胡萝卜素(P <0.05),羟自由基清除率显著高于α-生育酚、BHA、特丁基对苯二酚(tert-butyl hydroquinone,TBHQ)和β-胡萝卜素(P <0.05),总还原力显著高于α-生育酚和β-胡萝卜素(P <0.05);类胡萝卜素在避光、低温及不含K⁺、Na⁺、Mg²⁺、Ca²⁺、Ba²⁺、Cu²⁺、Fe³⁺的条件下较稳定。研究结果表明好食脉孢霉类胡萝卜素具有较强的抗氧化活性,具有开发为天然抗氧化剂的巨大潜力。