【作者】 章宝；

【导师】 单杨；

【作者基本信息】 中南大学 ， 食品科学与工程， 2012， 硕士

【摘要】 花生是世界上最重要的油料作物之一,也是重要的蛋白资源。花生仁脂肪含量在50%左右,蛋白质含量达24%-36%。在植物蛋白资源中,花生蛋白为蛋白总量的11%,位居第三,是非常理想的食用蛋白资源。传统的制油方法主要有压榨法和溶剂浸出法,压榨法残油率高,动力消耗大,劳动强度大,而溶剂浸出法存在有机溶剂残留问题,花生蛋白也不能充分利用。因此,探索一种提油率高、无有机溶剂残留,同时所得蛋白变性低的分离花生油和花生蛋白的新工艺是十分必要的,也是具有现实意义的。超临界C02萃取技术作为一种绿色工艺,克服了传统压榨法收率低和溶剂提取法有机溶剂残留等问题,显示出巨大的市场潜力。本论文的主要研究内容和结果如下。采用超临界C02流体萃取技术萃取花生油。通过单因素试验及响应面优化试验研究了萃取压力、萃取温度、C02流量、萃取时间和花生仁粒度等因素对花生油萃取率的影响,确定了超临界C02萃取花生油的最佳工艺条件。试验结果表明,在试验范围内各影响因素对花生油萃取率作用的大小顺序依次为：萃取温度>萃取时间>萃取压力。超临界C02萃取花生油的最佳工艺参数为：萃取压力24MPa,萃取温度43℃,花生仁粒度20目,C02流量为20L/h,萃取时间110min,在该工艺条件下花生油萃取率达到96.16%。以有机溶剂提取法为对照,采用超临界二氧化碳萃取花生油,气相色谱-质谱联用技术(GC-MS)对花生油成分进行分析,NIST10质谱数据库对其进行分析和鉴定。结果表明,SFE-CO2萃取法共分离鉴定出12种物质,饱和脂肪酸主要成分是棕榈酸(11.27%),占脂肪酸总量的20.11%；不饱和脂肪酸主要成分是油酸(45.68%)和亚油酸(32.42%),占脂肪酸总量的79.32%。采用有机溶剂提取法共鉴定出9种物质,饱和脂肪酸主要成分是棕榈酸(11.30%),占总脂肪酸总量的21.07%；不饱和脂肪酸主要成分是油酸(44.79%)和亚油酸(32.31%),占脂肪酸总量的78.14%。SFE-CO2流体萃取的花生油不饱和脂肪酸含量较高,且酸价低、过氧化值低,油的品质明显优于有机溶剂提取的花生油。采用碱提酸沉法从低变性花生粕中提取花生分离蛋白,以花生分离蛋白提取率为响应值,应用Box-Behnken对碱提温度、时间、液料比和pH值4因素进行响应面分析,确定碱提的最佳工艺条件为：碱提温度57.5℃,时间100min,液料比12：1和pH9.2；通过单因素试验确定最佳酸沉pH值为4.5。在此条件下,花生分离蛋白最高提取率为87.57%,与预测值87.88%相对误差为0.4%。以提取花生分离蛋白剩下的残渣和低变性花生粕为原料,经超微粉碎等工艺生产出花生粕,将其与全脂奶粉混合生产花生蛋白奶粉,所得产品溶解度高、冲调性好、口感细腻,营养均衡,同时具有奶味和花生特有的香味。更多还原

【Abstract】 Peanut is one of the most important oilseeds and an important protein resource in the world. The oil content of peanut is about50%and the protein content is24%-36%. Peanut protein is an ideal food protein resource, which accounts for11%of the total protein in the top three plant protein resources. The classical processing methods for peanut oil include mainly pressing and soaking with organic solvent. However, both the main methods are of imperfection, the pressing way with high residual oil rate, labor intensive and energy consumption, and the solvent extraction with residual organic solvents and the protein under-utilization. It’s necessary to find a new method that could extract oil from peanut with high oil extraction rate and no residual organic solvents. The supercritical carbon dioxide fluid extraction technology is known as green technology, which could solve the problems of the traditional methods with huge market potential. The main conclusions of this paper were as follows:A method utilizing supercritical CO2fluid extraction (SFE-CO2) technology to extract peanut oil was described. The optimum technological conditions were obtained by single-factor and response surface experiments, and parameters that affect extraction rate, such as peanut granularity, extraction pressure, time, temperature and supercritical CO2flow were investigated. The order of factors that influenced the oil extraction rate was as follows:extraction temperature> extraction time> extraction pressure. The highest extraction rate96.16%was achieved in the optimum extraction conditions with20mesh peanut at20L/h CO2flow in the pressure of24MPa for110min at43℃.12compositions had been extensively determined in peanut oil by SFE-CO2method on the basis of gas chromatograph-mass spectrometer (GC-MS,NIST10spectral database) detection methods. Saturated fatty acids (mainly palmitic acid,11.27%) and unsaturated fatty acids (oleic,45.68%and linoleic,32.42%) in the SFE-CO2extracts were20.11%and79.32%, respectively. While,9compositions were identified by GC-MS in the organic solvent extracts. The saturated fatty acids and unsaturated fatty acids in the extracts were21.07%(palmitic acid,11.30%) and78.14%(oleic,44.79%and linoleic,32.31%), respectively. Compared with the organic solvent extraction method, the peanut oil by SFE-CO2method with higher content of unsaturated fatty acids, lower acid value and peroxide value, was obviously superior in quality.Peanut protein isolate was prepared through alkali extraction and acid precipitation from low variability peanut meal. The optimal values of theoretical parameters including extraction temperature, ratio of liquid and material, extraction time and extraction pH were investigated by Box-Behnken surface response design method. The optimum conditions of alkaline extraction:extraction temperature57.5℃, pH9.2, ratio of liquid and material12:1and extraction time100min, based on the single-factor test, the optimum pH4.5of acid precipitation were determined. Under these conditions, a maximum protein extraction rate of87.57%was obtained. The relative error with predicted value was0.4%.Peanut protein milk powder was prepared by the ultramicro-porwderized protein isolate residues and low-denature peanut meal, mixing with whole milk powder. The products had the peculiarity of both milk flavor and peanut-specific flavor with high solubility, good dissolving ability, smooth taste and balanced nutrition.更多还原