初榨橄榄油中的微生物群及其对橄榄油品质的影响

初榨橄榄油生产环境相对开放,榨取橄榄油的原料、环境及设备中的微生物群都可能进入初榨橄榄油,对油脂品质产生影响。为全面认识初榨橄榄油中微生物群以及从微生物层面控制初榨橄榄油品质,从食品微生物学研究的视角,综述了初榨橄榄油中酵母菌、细菌和霉菌等主要微生物群,分析了油橄榄枝叶、果实和初榨橄榄油中的微生物群对油脂品质的影响,介绍了采后储存的油橄榄果实及储存期的初榨橄榄油品质与微生物群之间的关系,探讨了对有害微生物群影响初榨橄榄油品质的防控措施。研究认为酵母菌对初榨橄榄油储存期间的品质起主要的影响作用。通过避免采摘和储存过程中油橄榄果实的损伤,保证加工过程中清洗用水和设备的洁净,控制储存环境温度、光照和氧含量等措施,可以有效防控有害微生物对橄榄油品质的负面影响。

基于三维荧光特征峰的橄榄油品质鉴别研究

由于特级初榨橄榄油的国家标准中各项理化指标检测需要昂贵的理化分析仪器及相关专业人才,使得橄榄油市场的监管力度受到严重制约。为此,通过采集特级初榨橄榄油、精炼橄榄油及其他品种食用植物油的三维荧光光谱,提取它们各自的特征荧光峰,建立基于三维荧光特征峰区域积分比值的橄榄油品质分析算法。然后,对四个不同品牌特级初榨橄榄油、精炼橄榄油及特级初榨橄榄油掺杂体积分数10%~50%精炼油的混合油样测试,得到橄榄油品质因子动态范围为37 dB,能够有效鉴别不同比例掺杂样品、品牌特级初榨橄榄油和伪劣特级初榨橄榄油,实验结果表明,其敏感性和特异性远优于样品的三个传统理化指标。此荧光分析法所需的荧光光谱数据量小,可以为实现橄榄油品质的低成本、快速鉴定提供新的理论依据。

油橄榄粉碎融合关键技术的研究

橄榄油是从油橄榄果肉中制取的植物油,需要预先将果肉粉碎,而在使用金属粉碎机粉碎橄榄果时,由于其剧烈振动,通常会导致产生乳状的橄榄糊,从而减少油的产量。本文根据我国橄榄油生产企业的实际情况,以全程加工工艺为基础,研究形成了高品质橄榄油加工中粉碎融合关键技术及装备。研究表明:融合45min后,乳液可减少,出油率增加。在一定时间范围内,出油率与融合时间呈正相关关系;随着融合时间的增加,橄榄油的酸值、过氧化值没有明显的差异,但总酚含量显著减少。

Sensory Evaluation of Extra Virgin Olive Oil （EVOO） Extended to Include the Quality Factor ＂Harmony＂

Sensory evaluation of olive oil, meaning the official organoleptic assessment of olive oil respectively the ＂Panel Test＂ （PT）, is based on the standards of the International Olive Council （IOC）, as well as on the Regulation （EC） 640/2008 of the European Commission. These regulations lead to the classification of olive oil as ＂extra virgin＂ （EVOO）, ＂virgin＂ （VOO） or ＂lampant＂, which however is not sufficient to clearly discriminate between different quality levels within the grade EVOO. The objective of the study at hand was to develop and validate an objective sensory evaluation method for the quality certification of olive oil within the grade EVOO. A new rating system, including a detailed description and evaluation of the complexity and persistence of flavour, was established. First, a comparison between different profile sheets from various olive oil competitions （Ercole Olivario, Premio Biol, Leone D＇Oro Mario Solinas Award, among others） and the official profile sheet from the IOC/EC for the panel test （PT） took place. In consecutive steps the basic test procedure from the panel test （PT） then was extended with additional sensory descriptors. Two trained olive oil panels （the German Olive Oil Panel （DOP） and the Swiss Olive Oil Panel （SOP）） were further educated to profile various green and ripe aroma components and to evaluate the complexity of the perceived aroma components and their persistency （descriptor： ＂harmony/persistency＂）. This extended methodology was cross-validated over a time period of 3 years between the two panels （DOP/SOP）.