果酒中活性羰基化合物的研究进展

果酒多由水果发酵制备,其香气浓郁,且富含多种营养成分,深受消费者喜爱。但目前国内果酒行业发展处于上升阶段,产品质量良莠不齐,对于果酒生产和储藏过程中,可能产生的潜在危害物——活性羰基化合物(reactive carbonyl species, RCS)关注度不够。RCS不仅能破坏人体细胞正常生理功能,引发多种慢性疾病,还会对果酒品质造成不良影响。本文介绍了果酒中潜在危害物RCS的种类和危害、形成路径、含量以及分析方法,分析了果酒中富含的多酚类化合物对RCS的抑制活性、作用机制及其在食品中的应用,为果酒行业今后的开发方向及发展提供一定的理论基础和借鉴依据。     

基于Illumina PE300高通量测序的海南糟粕醋微生物多样性分析

目的 研究海南糟粕醋中微生物的多样性,分析海南糟粕醋在自然条件下贮藏时的优势菌及风险菌。方法 采用Illumina PE300高通量测序技术对海南糟粕醋中细菌和真菌群落进行多样性分析,扩增糟粕醋中细菌的16S rDNA和真菌的ITS序列。结果 细菌多样性测序获得306,600条序列, 130,745,424碱基(base pair, bp),505操作分类单元(operational taxonomic units, OTU),可归属为23门(phylum)、51纲(class)、115目(order)、191科(family)、312属(genus)、432种(species);真菌多样性测序获得612,015条序列, 132,784,567 bp, 27 OTU,可归属为3 phylum、7 class、12 order、18 family、24 genus、25 species。糟粕醋在自然条件下贮藏时,主要细菌属为:乳酸菌属(Lactobacillus)、棒杆菌属(Corynebacteriums)、乳酪短杆菌属(Brevibacterium)、芽孢杆菌属(Bacillus)、...     

电子束辐照对新疆干果品质的影响及其最高耐受剂量的确定

目的 探究电子束辐照对4种新疆干果品质的影响,确定干果辐照工艺的最高耐受剂量。方法 采用0、2、4、6、8和10 kGy不同剂量电子束处理枸杞干、红枣干、无花果干、小白杏干,研究不同辐照剂量对水分、维生素C、总酸、总糖4种理化指标及色度、外观、风味、色泽和口感等5种感官品质的影响。结果 仅8 kGy辐照处理对枸杞干口感指标有不良影响,其他3种干果的感官指标几乎不受辐照处理的影响; 10 kGy以内的辐照处理对红枣干的品质无不良影响;无花果干的总酸含量在辐照剂量>6kGy时有所上升,维生素C含量在10 kGy处理时显著低于对照;辐照剂量≥6 kGy时,小白杏干维生素C含量显著降低。结论 通过对电子束辐照新疆干果的品质影响及最高耐受辐照剂量的研究,确定枸杞干、红枣干、无花果干和小白杏干的最高耐受剂量分别是8、10、6和6 kGy。为电子束辐照在新疆干果灭菌工艺中的应用提供了理论基础。     

浅探水果快递纸箱的绿色化优化思路与方法

近年来,由于人们消费观念的转变,水果电商快速发展,由此带来大量水果快递包装。本文以水果快递纸箱这一特定领域,分析了目前水果快递纸箱的环保现状,从选材、设计与回收等方面,提出了水果快递纸箱的绿色化、可循环、标准化与减量化的优化思路与方法,为水果快递纸箱的设计、开发与生产提供有效借鉴。     

Biosorption of chromium (VI) from aqueous solution by seed powder of prickly pear (Opuntia ficus indica L.) fruits

ABSTRACT

The solid residue of the cold press oil extraction from prickly pear (Opuntia ficus indica L.) fruit seeds was evaluated as a low-cost biosorbent for biosorption of Cr(VI) from aqueous solutions. Batch experiments were conducted as a function of initial pH, contact time, biosorbent dose, initial Cr(VI) concentration, and temperature. Biosorption was highly pH-dependent and found to be maximum at pH 1.0. Langmuir and Freundlich equations fitted very well with experimental data. The maximum monolayer adsorption capacity was 19.61 mg/g at 298 K and pH 1.0. Biosorption kinetics was controlled by the pseudo-second-order model. Thermodynamic parameters indicated that biosorption of Cr(VI) was a spontaneous, favorable and endothermic process. The activation energy was found to be 40.68 kJ.mol^?1.     

Corrosion inhibition of mild steel in 1 M HCl using Tamarindus indica extract: electrochemical,surface and spectroscopic studies

Abstract

We report, here, the corrosion inhibition of mild steel specimen in 1?M HCl by tamarind fruit pulp aqueous (TFPA) extract. The inhibition property in the presence of TFPA extract is studied using weight loss, polarization measurement and electrochemical impedance spectroscopy (EIS). The inhibitor efficiency is found to vary from 74% to 88% (weight loss method) with TFPA concentration of 100–600?ppm. The reduction in Tafel slopes shows that TFPA acts as a mixed-type inhibitor. The adsorption of the inhibitor on the metal surface follows Langmuir isotherm. The standard Gibbs free energy of adsorption value of –40?kJ/mol suggests the chemisorption of inhibitor molecules via coordinate bond. AFM results exhibit a decrease in the surface roughness of mild steel, exposed to 1?M HCl from 299?±?12 to 154?±?6.6?nm, with increasing concentration of inhibitor from 0 to 600?ppm due to the uniform coverage of inhibitor molecules on the metal surface. X-ray photoelectron spectroscopy de-convoluted high resolution profiles of C 1?s (carbon) for mild steel exposed to 1?M HCl with 600?ppm inhibitor show major peaks corresponding to sp³ C–C/C–H (284.9?eV) and oxygen bondings in C–OH, C=O, COOH with a binding energy of 285.9, 286.9, 288.5?eV, respectively, thereby confirming the adsorption of organic moieties on mild steel surface. Fourier transform infrared spectroscopy further confirms the adsorption of inhibitor molecules on the metal surface. Therefore, tamarind fruit pulp extract is a potential corrosion inhibitor for mild steel, which is cost-effective, green and non-toxic.     

Antioxidant Activity of Rambutan (Nephelium lappaceum L.) Peel Extract in Soybean Oil during Storage and Deep Frying

Rambutan (Nephelium lappaceum L.) peel (RBP) is discarded as the main by‐product during processing of the fruit. Increasing attention is now paid to the valorization of RBP for the recovery of valuable compounds. Geraniin, ellagic acid, quercetin, and rutin are the main phenolic compounds found in methanolic RBP extract. Extracted rambutan peel powder (ERPP) is used to evaluate the oxidative stability of soybean oil stored at 4 and 30 °C in the dark and light and deep fried with potatoes at 160 °C. Tert‐butylhydroquinone (100 µg g^?1 oil, TBHQ) serves as positive control. Oil supplemented with ERPP of 1000 µg gallic acid equivalents (GAE) g^?1 of oil shows positive effects on the retardation of the oxidation process during storage in comparison with oil without addition. During deep frying, either ERPP (1000 µg GAE g^?1) or TBHQ retards the lipid oxidation of oil. Levels of thiobarbituric acid reactive substances of potatoes fried in oil fortified with the extract and TBHQ (0.4–0.59 µg g^?1) are much lower than those without the extract (1.31 ± 0.10 µg g^?1) (p < 0.05). Therefore, RBP extract exhibits favorable antioxidant effects and can be used for effectively inhibiting lipid oxidation in oil during storage and deep frying. Practical Applications: An extract from rambutan fruit peel containing phenolic compounds, that is, geraniin, ellagic acid, rutin, and quercetin showed promising results to be used as potential antioxidants in soybean oil during deep frying. Both oxidation of the frying oil as well as the oxidation of the food product, that is, potatoes were inhibited. These results demonstrated that rambutan fruit peel extract can be used as a natural antioxidant in frying oil to replace synthetic antioxidants, that is, TBHQ.     

Mechanical Properties of Benzoylated Oil Palm Empty Fruit Bunch Short Fiber Reinforced Poly(vinyl chloride) Composites

The influence of untreated and benzoylated oil palm empty fruit bunch (OPEFB) short fiber loading on the mechanical properties of the poly(vinyl chloride) (PVC) composite was studied. Benzoylated OPEFB was produced by mixing OPEFB with NaOH solution and agitating vigorously with benzoyl chloride. The PVC resin, various additives, and OPEFB were first dry blended using a laboratory mixer before being milled into sheets on a two-roll mill at 165°C and then hot pressed into composite samples at 180°C. The tensile and impact strength of untreated and benzoylated OPEFB composites decreased whereas the tensile modulus increased with increasing fiber loading from 0 to 40 phr. However, the benzoylated OPEFB was able to improve the tensile properties and impact strength of composites when compared to the untreated fiber. The enhancement of mechanical properties showed that the treatment improved the OPEFB fiber-PVC matrix interfacial adhesion. The improvement of adhesion was clarified by SEM micrographs, the increase of water resistance, and the reduction of glass transition temperature of the composites.     

两种甲酯化法比较微波辅助及超临界CO2提取琼榄果实油的成分

以南药琼榄果实为原料,采用微波辅助提取法(MAE)和超临界CO2提取法(SFE-CO2)提取琼榄果实油,并用气-质联用仪(GC-MS)比较了琼榄油经碱催化和BF3-MeOH催化甲酯化后的脂肪酸成分及其相对质量分数。结果表明,两种方法所提取琼榄油的脂肪酸成分大致相同。GC-MS分析MAE(碱催化法)、SFE-CO2(碱催化法)、MAE(BF3-MeOH催化法)、SFE-CO2(BF3-MeOH催化法)这4种方法所得的琼榄果实油,其中相对质量分数最高的是十八碳烯酸(69.44%、69.04%、64.92%、64.69%),次之为棕榈酸(20.82%、21.01%、21.45%、21.70%),再次是亚油酸(6.33%、6.03%、6.33%、6.13%)。不饱和脂肪酸占脂肪酸总量分别高达76.75%、75.91%、74.77%、74.30%。     

Improving supercritical water gasification of sludge by oil palm empty fruit bunch addition: Promotion of syngas production and heavy metal stabilization

The co-gasification of sewage sludge and palm oil empty fruit bunch (EFB) in supercritical water (SCW) was conducted at 400℃ with a pressure of over 25 MPa. This study aimed to investigate the influence of EFB addition on the syngas production and its composition. The heavy metal distribution and the leaching potential of the solid residue were also assessed. The results showed that syngas yield significantly increased with the addition of EFB into the feedstock. The cold gas efficiency (CGE) and carbon efficiency (CE) of co-gasification were higher than those of individual gasification. The actual syngas production from co-gasification of sludge and EFB was 45% higher than the theoretical total volume. The results indicated that the addition of EFB to sludge had the synergetic promotion effect on syngas production from sludge and EFB in supercritical water. This enhancement might be due to the dissolution of alkali metals from EFB and the adjustment of organic ratio. In addition, higher percentage of heavy metals were deposited and stabilized in the solid residue after SCWG. The leaching concentration of heavy metals from the solid residues was decreased to a level below the standard limit which enables it to be safely disposed of in landfill. In conclusion, the EFB addition has been proved to promote syngas production, as well as, stabilize the heavy metal in solid residues during co-SCWG.