Mineral composition of frozen green asparagus

The contents of macroelements (Ca, Mg, Na, K y P) and trace elements (Cu, Fe, Zn and Mn) of frozen green asparagus were determined by atomic absorption spectrometry to investigate the possible changes during 45 and 90 days frozen storage at –18 °C. A significant decrease of mineral concentrations was observed at 45 days of frozen storage. After 90 days, modifications were not observed, except for Cu and P concentrations. The asparagus thickness factor resulted in significant differences in the Cu, Fe, Zn, Ca and K contents. Frozen storage time involved smaller percentages of mineral retention in the <11 mm spear for Ni, Ca, Mg, K and P, and, for the rest of mineral elements, the frozen storage effect was similar for both thicknesses (<11 mm and >14 mm). The highest mineral concentration was found in the apical portion or tip of green asparagus, except for Mn, Cr and K. Mineral retention percentages after frozen storage time were similar in both portions (apical and basal) of the spear.     

Physical and chemical changes in minimally processed green asparagus during cold-storage

The purpose of this research is to study effects of an innovative packaging method on the shelf-life of minimally processed green asparagus. The physical–chemical parameters analyzed (weight loss, colour, texture, chlorophyll and citric acid), and monitored by untrained panellists during the cold storage period at 6 °C, showed that pairing of a semi-permeable film with an adsorbent material and immersion in ascorbic acid solution were able to extend the shelf-life of green asparagus. Also, on the basis of the results obtained, a study of the chlorophyll and toughness degradation kinetics of green asparagus was conducted during cold storage. These data showed the toughening of asparagus spears to be faster than chlorophyll degradation. Thus, the former can be used as a reliable quality index to predict the shelf life of such products.     

Cell wall phenolics of white and green asparagus

Cinnamic acids influence physical and textural attributes of plant foods as they play an important role in lignification and cross‐linking of cell‐wall polymers. Several trans‐cinnamic acids have been detected in asparagus cell wall (CW), and, of these, amounts of ferulic acid (FA) and its dehydrodimers have been found to increase significantly during post‐harvest storage. The distribution of these compounds along the different sections of white and green spears, as well as their modifications during postharvest storage, has been investigated. It has been observed that the cell walls from the apical, middle and lower sections of the green spears contain equivalent amounts of FA derivatives (about 400 µg g^?1 CW), while these compounds are mainly located in the middle (681 µg g^?1 CW) and lower section (975 µg g^?1 CW) of the white ones. During asparagus post‐harvest storage a general increase of FA monomers and dimers took place that affected every section of both green and white spears. Major changes occurred in the middle and lower sections of the white asparagus, where the amounts of ferulic derivatives increased to 1700 and 1678 µg g^?1 CW after storage. A similar but less pronounced trend was observed for the green spears. Copyright © 2005 Society of Chemical Industry     

绿芦笋不同部位营养成分及活性评价研究

对绿芦笋不同部位的营养成分及其抗氧化活性进行测定分析。结果表明,绿芦笋四个部位的营养成分和抗氧化活性存在显著差异(p<0.05);绿芦笋叶和嫩尖中含有较高含量的蛋白质、粗脂肪,叶和嫩茎中含有较高含量的总糖和还原糖;四个部位均含有多种矿物质元素,其中K、Ca、Mg、Fe等元素含量较高;四个部位均含有16种氨基酸,包括8种必需氨基酸,其中天冬氨酸、谷氨酸、赖氨酸、亮氨酸含量较高;对活性物质分析得出新鲜绿芦笋叶中皂苷、黄酮含量最高,分别为1.33g/100g鲜重、0.48g/100g鲜重;四个部位水提物和醇提物均有一定的抗氧化能力,其中绿芦笋叶抗氧化能力显著高于其他三个部位(p<0.05)。绿芦笋营养价值较高,有很好的开发前景。      

Mechanical properties of green asparagus

The mechanical properties of three sections (upper, middle and lower) of the spears of green asparagus (Asparagus officinalis) were investigated as affected by storage and cooking. A range of methods based on cutting, compression and puncture was employed to measure mechanical properties of spear sections. A transverse puncture test was the most suitable for measuring mechanical properties of fresh and cooked spear sections, and it was observed that strength increased along the spear from the upper to the lower section of fresh asparagus. Postharvest storage resulted in strengthening, mainly located in the last portion of the stem. A softening phenomenon was detected in every section as a consequence of cooking. The results of a tensile test on two different tissue types separated from the middle and lower portions of the stem showed that the external tissues were stronger and stiffer than the internal tissues, and both increased in strength and stiffness after 3 days of storage. However, the effect of cooking was different: while the external tissues decreased in stiffness and strength, as expected, a significant increase was observed for the internal tissues of the stem. © 2002 Society of Chemical Industry     

绿芦笋真空干燥工艺研究

主要研究了绿芦笋的真空干燥工艺条件,以漂烫温度、漂烫时间、干燥温度和工作压力为因素,通过L16(45)正交试验,确定漂烫和真空干燥的最佳工艺条件为85℃热水中漂烫4min、干燥温度为75℃、工作压力为0.03MPa。     

芦笋提取物抗疲劳及耐缺氧活性研究

目的:研究芦笋提取物抗疲劳及耐缺氧活性。方法:以75%乙醇为溶媒,超声提取芦笋,获得芦笋乙醇提取物,对提取物中总皂苷、总多糖、氨基酸进行含量分析;整体口服给药实验观察芦笋乙醇提取物对小鼠抗疲劳及耐缺氧功能的影响,给药剂量分别为25、100、400mg/kgmb。结果:给药14d后,小鼠负重游泳时间均显著延长（低、高剂量组p<0.01,中剂量组p<0.05）;给药30d后,无负重游泳30min小鼠血乳酸含量显著下降（低、中剂量组p<0.01,高剂量组p<0.05）,血尿素氮（BUN）含量没有显著性变化（p>0.05）,肝脏谷胱甘肽过氧化物酶（GSH-PX）含量显著升高（低、中剂量组p<0.05,高剂量组p<0.01）,过氧化物歧化酶（SOD）含量显著升高（低剂量组p<0.01,中、高剂量组p<0.05）,高剂量组丙二醛（MDA）含量显著下降（p<0.05）;给药30d后,高剂量组小鼠常压密闭存活时间显著延长（p<0.05）,注射盐酸异丙肾上腺素后,各剂量组小鼠耗氧量及存活时间均无显著变化。结论:芦笋乙醇提取物有明显的抗疲劳功能及一定的耐缺氧功能。      

冷冻绿芦笋加工工艺及其质量控制

该文主要介绍冷冻绿芦笋的加工工艺，并对其重点工序的质量控制进行了阐述。采用此工艺加工的产品色泽鲜绿，口味鲜美，营养丰富。     

Kinetics of green asparagus ascorbic acid heated in a high-temperature thermoresistometer

 Thermal degradation of green asparagus ascorbic acid in high-temperature short-time conditions was studied by heating in a five-channel computer-controlled thermoresistometer. Ascorbic acid was heated to between 110  °C and 140  °C and the degradation kinetics were analyzed assuming that two different inactivation mechanisms were occurring, one aerobic and the other anaerobic. The two reactions followed first-order kinetics, with E _a=12.3(2.0) kcal/mol and k _125  °C=47.0(3.0)×10^–3 s^–1 for the aerobic oxidation, and E _a=6.1(1.4) kcal/mol and k _125  °C=4.1(0.2)×10^–3 s^–1 for the anaerobic degradation. Received: 30 January 1998 / Revised version: 11 June 1998     

绿芦笋保鲜技术研究

对绿笋采后呼吸、Vc变化规律及实用保鲜技术进行了研究。试验结果表明:芦笋为呼吸高峰型的蔬菜;采收后,Vc随着贮藏期的延长而逐渐下降;臭氧可明显地抑制笋尖白霉的生长,并对软腐病有一定的抑制作用;芦笋气调效应明显,在0.8～1.2℃的低温下,O22%～3%、CO213%～14%效果最好,贮藏30d商品率达90%以上。     

Effect of three-stage hypobaric storage on membrane lipid peroxidation and activities of defense enzyme in green asparagus

The effect of three-stage hypobaric storage on free radical content, membrane lipid peroxidation, activities of cell defense enzyme and surface color (L* value, a* value and b* value) in green asparagus was studied as compared with the atmosphere cold storage. The three-stage hypobaric condition significantly increased the activities of superoxide dismutase (SOD) and catalase (CAT), decreased the accumulation of malondialdehyde (MDA), superoxide anion (O₂⁻) and hydrogen peroxide (H₂O₂), inhibited the increase of relative leakage rate, delayed the degeneration of surface color, and controlled the increase of peroxidase (POD) activity. It was concluded that three-stage hypobaric storage could obviously inhibit asparagus senescence and that the storage life of 50 days could be achieved as compared with the storage life of only 25 days in atmosphere cold condition.     

Mechanical properties of white and green asparagus: changes related to modifications of cell wall components

The changes of texture that take place in white and green asparagus during storage and cooking are, in large part, determined by the composition and structure of the cell walls. Several instrumental methods have been applied to three sections of the spears to investigate the physico‐chemical properties that contribute to the values of texture. Cutting the spears with a razor blade is the most appropriate method for quantifying and comparing the texture of white and green asparagus and, among the different parameters that can be calculated from the curves registered during asparagus cutting, strength and toughness have been used for determining changes of texture. Post‐harvest storage caused an increase of texture mainly located in the lower portions of the white spears. The process of toughening also affected the lower section of the green spears, but to a lesser extent. Cooking resulted in a softening, mostly in the apical section of the stem. Additional information about the physico‐chemical properties of different plant tissues has been obtained by applying a tensile test to the internal and external tissues separated from asparagus sections. Copyright © 2004 Society of Chemical Industry     

绿芦笋富锗鲜湿面条的研制

绿芦笋富锗鲜湿面条是一种高营养的绿色保健新产品,该产品具有营养价值高、外观形态好、适口性强等特点。通过实验研究,其最佳生产配方为:面粉55%、绿芦笋汁25%、富锗豆芽粉3%、水适量、淀粉4.5%、谷肽粉0.5%、食盐0.2%、瓜儿豆胶0.2%。     

Degradation of malathion in aqueous extracts obtained from different developmental stages of asparagus (Asparagus officinalis)

When malathion was incubated in aqueous extracts obtained from 17 vegetables and fruits at pH 7.4 and 37 °C for 4 h, asparagus extract exhibited the highest malathion degradation. The degradation effects of the extracts ranged from 100% (asparagus) to 0.5% (papaya). The highest malathion‐degradation effects obtained from extracts of asparagus at different growing stages incubated at pH 7.4 and 37 °C for 1 h was 94.4 ± 0.45% (stem length, 5–10 cm), followed by 88.0 ± 0.31% (10–15 cm), 85.1 ± 0.94 (15–20 cm), 82.2 ± 0.52 (20–25 cm), 81.2 ± 1.4% (pre‐emergent), 67.3 ± 0.67% (>25 cm), and 42.7 ± 2.1% (fern). The protein content in an asparagus extract from different growing stages was not consistent with the degradation activity of malathion. Results of time course studies on malathion degradation in asparagus extracts from different growing stages yielded half‐life times of malathion degradation ranging from 51.7 min (fern stage) to 17.3 min (stem length, 5–10 cm). Formation of α‐ and β‐malathion mono acids from malathion was detected in an incubated sample by gas chromatography/mass spectrometry. The results support the presence of carboxylesterases in asparagus extracts. Copyright © 2006 Society of Chemical Industry     

不同制汁工艺对绿芦笋汁理化成分和抗氧化活性的影响

以绿芦笋为材料,研究了直接破碎制汁、热烫后破碎制汁、热烫后破碎经纤维素酶处理制汁、冷冻芦笋解冻后破碎制汁四种工艺对绿芦笋汁理化成分和抗氧化活性的影响。结果表明:热烫处理能保护芦笋汁的色泽,提高VC的稳定性;纤维素酶处理能提高芦笋汁的可溶性固形物、总糖及总黄酮含量及其抗氧化活性;热烫和纤维素酶处理均能降低芦笋汁中的可溶性蛋白和总酚含量。      

绿芦笋防腐保鲜技术研究

研究了几种保鲜液对绿芦笋防腐保鲜的效果,并初步探讨了应用高吸水性树脂防止保鲜袋内结露的技术。结果表明,4种防腐保鲜液浸蘸笋尖均可明显地抑制贮藏过程中芦笋软腐病的发生,但以双乙酸钠处理效果最好,贮藏至40d、45d,对照已全部发病,而用1.5%双乙酸钠处理的,发病率为0和32%。0.5%中生菌素、1.5%的双乙酸钠和1%氯化钠处理,均有延缓芦笋叶绿素分解的作用。双乙酸钠处理还可以较好地抑制MDA含量的增加并有延缓果胶分解的效果。4种防腐保鲜液处理均不能抑制芦笋纤维素含量的增加。高吸水性树脂在一定时间内具有理想的防结露效果,但适宜使用剂量和包装方式尚需进一步研究。     

减压贮藏对绿芦笋不同部位品质的影响

以绿芦笋为原料,研究不同减压条件对绿芦笋不同部位品质的影响。结果表明,减压贮藏可以明显抑制可溶性蛋白质和可溶性固形物(TSS)含量的降低,0·06MPa作用显著。不同部位的绿芦笋可溶性蛋白质含量和TSS的变化趋势不同;中部和根部的可溶性蛋白质和TSS的含量随着贮藏期的延长逐渐降低,而茎头部呈略升后降趋势;绿芦笋叶绿素含量呈下降趋势,0·02MPa条件保存了较高的叶绿素含量,绿芦笋的不同部位色度a*值随着贮藏期的延长由负值逐渐变为正值,与对照相比,0·04MPa和0·06MPa对绿芦笋护绿作用不明显,0·06MPa减压贮藏效果好于0·02MPa和0·04MPa贮藏的效果,但色度a*值反而较大。      

包装容器对绿芦笋汁货架期品质的影响

绿芦笋汁采用121℃、3min杀菌处理后,分别灌装于预先杀菌处理的玻璃瓶和聚对苯二甲酸乙二醇酯（PET）瓶中,于（4±1）℃冷藏,通过测定绿芦笋汁贮藏期间色泽、叶绿素、类胡萝卜素、维生素C、总酚和还原糖含量的变化,以探究不同包装容器对绿芦笋汁贮藏期间品质的影响。结果表明:玻璃瓶包装可有效延缓绿芦笋汁冷藏期间色泽亮度的上升和绿色的受损,抑制类胡萝卜素含量的上升,从而有效地保护绿芦笋汁的绿色,维持绿芦笋汁色泽的稳定性,在贮藏结束时L*值为56.15,a*值为-1.27,总叶绿素含量为5.584mg/L;玻璃瓶装绿芦笋汁的维生素C、总酚和还原糖含量的降低受到显著抑制,尤其是维生素C含量在贮藏3个月时仍为0.204mg/m L,保留率为82.93%,总酚和还原糖的保留率分别为52.74%、64.58%,而PET瓶装绿芦笋汁的维生素C、总酚和还原糖的保留率分别为28.05%、43.68%和58.67%。由此,玻璃瓶包装可有效维持绿芦笋汁冷藏期间的货架品质。      

热杀菌结合冷藏改善绿芦笋汁的贮藏稳定性研究

为研究热杀菌处理对绿芦笋汁贮藏稳定性的影响,通过121℃、3min(F03min)处理绿芦笋汁,并置于(4±1)℃条件下冷藏,定期测定其各指标(菌落总数、色泽、可溶性蛋白、总糖、总酚、总黄酮、VC含量与DPPH自由基清除能力)的变化。结果表明:F03min热杀菌处理可将芦笋汁中的固有微生物完全杀死,且在芦笋汁冷藏的120d均无微生物生长;F03min杀菌处理结合冷藏可有效抑制绿芦笋汁贮藏期间L*和a*值的上升,延缓可溶性蛋白、VC、总酚和DPPH自由基清除能力的下降,维持总糖和总黄酮含量的稳定,保持绿芦笋汁的贮藏稳定性,有效延长绿芦笋汁的贮藏货架期,使其冷藏期延长至120d。      

水溶性壳聚糖涂膜处理对采后绿芦笋贮藏品质的影响

研究了0.50%的水溶性壳聚糖(WSC)和羧甲基壳聚糖(CMC)分别对在2℃贮藏条件下采后绿芦笋的涂膜保鲜。通过感官品质、失重率、抗坏血酸含量、叶绿素含量、丙二醛(MDA)含量、总酚含量、多酚氧化酶(PPO)等生理生化指标的测定,以未经处理的绿芦笋为对照。结果表明:经0.50%的CMC和WSC进行涂膜处理,均可有效地降低芦笋的失重率,维持其硬度,延缓其抗坏血酸和叶绿素营养物质的消耗。而且CMC处理可以明显抑制绿芦笋总酚含量的下降及其PPO、POD和SOD活性的变化,其感官品质也明显优于对照组,使绿芦笋的贮藏时间延长至35 d。