刺梨果渣的干燥模型建立及品质分析

为科学合理地选择刺梨果渣干燥保藏实用技术,以减少果渣原料品质变化和营养损失。以刺梨果渣为原料,采用热风干燥、远红外干燥和真空干燥方式,构建果渣干燥模型,确定最佳干燥技术。结果表明:Midilli和Kucuk数学干燥模型具有较高的决定系数R~2,较低的χ~2、误差平方和及均方根误差,对3种干燥方式的拟合度最高,可以用来描述和预测刺梨果渣的干燥进程;远红外50℃干燥为果渣最优干燥方式,此条件下刺梨果渣品质指标最优,L*值为44.12,ΔE为6.87,果渣复水性为7.53,VC损失率为20.54%,黄酮含量为1.97 mg/g。     

Gasification performance of olive pomace in updraft and downdraft fixed bed reactors

This study aims to investigate the gasification potential of olive pomace with using different fixed-bed gasifier systems. Olive pomace as a dried form was supplied from a chemical industry plant working on olive oil soap, located in Izmir, Türkiye. After a complete characterization of olive pomace, gasification experiments by using fixed bed reactor systems were done at three different gasifier temperatures as 700, 800 and 900 °C. As a gasification agent, dry air was used with four different flowrates (0.4, 0.2, 0.1, 0.05 L/min) while pure oxygen experiments were carried out with a flow rate of 0.01 L/min. Syngas with H₂ content of 48% and 45% (volumetric) were obtained in updraft and downdraft gasifiers, respectively, by using dried air as a gasifying agent. Heating value of syngas was around 12.4 MJ/Nm³. In the pure oxygen atmosphere, H₂ contents of the syngas were measured as 53% and 39%vol. In the updraft and downdraft gasifiers. This paper presents the research results on the olive pomace gasification study as a part of a large-scale research project and discuss them in the context of hydrogen production from the fixed bed reactors.     

Partitioning of predominant lipophilic bioactives (squalene, α-tocopherol and β-sitosterol) during olive oil processing

The partitioning of predominant lipophilic olive bioactives (squalene, β-sitosterol and α-tocopherol) in olive oil processing was studied for the first time using common integrated olive milling plant. 7% of the oil and 5% of the squalene present in the olives was lost in the last pomace. β-sitosterol and α-tocopherol, which are mainly concentrated in the seed of the olive fruit, was recovered in virgin olive oil to a lesser extent (66%, 67%) while 10% were lost in last pomace. Thus, the loss of β-sitosterol and α-tocopherol was higher than that of squalene and oil, due to nonrecovered bound forms. 19% of the α-tocopherol and 21% of the β-sitosterol loss was unaccounted for, which can be attributed to degradation of α-tocopherol and incomplete recovery of sterols from the olive and pomace matrices. This study provides a basis for process development studies.     

Autochthonous white grape pomaces as bioactive source for functional jams

Seeds and skins from grape pomaces of Pecorello and Mantonico cv underwent extraction (ultrasound–assisted or maceration), in order to obtain added-value ingredients for the production of a functional pear jam. The antioxidant features of the extracts were tested by in vitro colorimetric assays. Among seeds, Mantonico by maceration (MSC) showed the best results, as well as Mantonico by ultrasound-assisted extraction (MBs) among skin extracts. The selected extracts were fully characterised by NMR and MS techniques, confirming the presence of many polyphenols, flavonoids and tannins among others. Pectin was then derivatised by the grafting procedure with the active molecules of MBs and MSC. The latter produced the best antioxidant polymer also without toxicity evaluated using Caco-2 cells and was used for the jam preparation. The functional pear jam showed improved antioxidant performances in comparison with its non-functional counterparts as well as its maintenance over time (15 days).     

苹果渣水不溶性膳食纤维的提取及脱色工艺研究

提出了以苹果榨汁生产线上的废渣为原料 ,采用碱液浸提法制备水不溶性膳食纤维的工艺流程。研究了料液比、碱液浓度、反应温度及提取时间对碱溶性半纤维素提取率的影响 ,得到最佳提取条件 ;并采用L9( 34)正交表对苹果渣食用纤维的脱色工艺进行了研究 ,找到了最佳脱色工艺条件。     

葡萄籽油的营养价值与生物活性综述

酿酒葡萄皮渣是葡萄酒加工副产物,包括葡萄皮、果梗和葡萄籽,其中葡萄籽中富含多酚、维生素、植物甾醇、不饱和脂肪酸等营养成分,具有极高的利用价值。该文在查阅大量国内外相关文献资料的基础上,详细阐述了葡萄籽油的营养价值、生理活性和利用现状,并对未来我国葡萄籽油的综合利用进行了展望,以期能为我国酿酒葡萄皮渣的有效利用提供一定的参考。     

葡萄果醋饮料的工艺研究

以玉米、麸皮为主要原料,经酒精发酵后加入葡萄皮渣进行醋酸发酵而制得葡萄果醋,再经调配,制成风味独特的葡萄果醋饮料。通过单因素实验、正交试验,优化了工艺条件和配方。结果表明,以玉米、麸皮汁为发酵基料,基料的糖含量为16°Brix,pH 3.5,酵母接种量为10%,发酵温度30℃,经酒精发酵6 d,酒精体积分数达到6%～7%时进入醋酸发酵,糖含量4°Bx,醋酸菌接种量10%,发酵温度30℃,醋酸发酵6 d。风味配方为:葡萄果醋10%,柠檬酸0.1%,蔗糖9%。     

沙棘果渣粉的超微冷冻粉碎制备及其理化性质与结构特性

沙棘果渣富含多种营养和功能成分,但其增值利用率较低。该研究以常温机械粉碎制得的沙棘果渣粉为对照组,对利用超微冷冻粉碎技术在主机频率20~50 Hz范围内制备不同细度的沙棘果渣粉进行功能成分、理化性质与结构特性方面的比较。结果表明：主机频率30 Hz制得粉末的可溶性膳食纤维、Vc含量和持水性最高,分别为7.63%、3.46 mg/100 g和25.12%,优于对照组的4.01%、2.28 mg/100 g和23.86%。主机频率40 Hz制得粉末的阳离子交换能力最强,达到1.82 mmol/L,优于对照组的0.92 mmol/L。主机频率50 Hz制得粉末的总黄酮溶出量、亮度、溶胀性、水溶性最高而中位粒径最小,分别为5.67 mg/g、71.16、8.10 mL/g、23.32%和21.72 μm,优于对照组的4.34 mg/g、65.57、6.17 mL/g、15.51%和325.91 μm。超微冷冻粉碎技术可以最大限度降低粉碎过程中热量对沙棘果渣粉中热敏性物质的破坏,改善粉碎产品的营养和功能成分保留率、溶出率以及功能特性,而主要结构及基团未发生较大改变。研究结果为沙棘果渣开发利用提供了理论依据。     

不同水解方法对刺梨渣多酚含量及活性的影响

该研究以刺梨渣为原料,分别经酸水解、碱水解以及酶水解得到刺梨渣提取液,测定提取液中多酚含量组成及体外抗氧化能力,并比较酚类物质与抗氧化能力之间的相关性。结果表明,刺梨渣提取液中游离多酚、游离黄酮含量最高（分别为84.44 mg RE/g和136.67 mg RE/g）;碱水解得到的结合酚、结合黄酮含量最高（2.04 mg RE/g和5.89 mg RE/g）。抗氧化分析结果表明,游离酚抗氧化能力最强,对DPPH·、ABTS+·清除能力、还原铁离子和铜离子的能力分别达到854.87 μmol TE/g、995.35 μmol TE/g、336.24 μmol TE/g、1 212.08 μmol TE/g。皮尔逊相关性分析结果表明,多酚含量与抗氧化活性呈较强的正相关（P＜0.05）。综上可知,刺梨渣富含酚类物质,且碱水解处理刺梨渣能释放更多的结合酚,具有较强的抗氧化活性。