Islam Mahbuba, Kaczmarek Anna, Grygier Anna, Tomaszewska-Gras Jolanta
Department of Food Quality and Safety Management, Poznań University of Life Sciences, ul. Wojska Polskiego 31/33, 60-624 Poznań, Poland.
Department of Food Technology of Plant Origin, Poznań University of Life Sciences, ul. Wojska Polskiego 31/33, 60-624 Poznań, Poland.
Foods. 2023 Aug 4;12(15):2954. doi: 10.3390/foods12152954.
An approach of implementing X-bar and R control charts as a statistical control tool to monitor the changes in the melting profile of fresh and stored flaxseed oils by differential scanning calorimetry (DSC) was used. Phase transition melting profiles were collected after 0, 2, 4, and 6 months of storing flaxseed oils, originating from five different cultivars. Four peaks at around -36, -30, -25, and -12 °C were identified using the deconvolution analysis procedure, which enabled the data to be collected at peak temperature (T), peak height (h), the peak area (A), and the percentages of the area (P A), as well as the ratio calculated from these parameters. Control charts obtained for the second peak of the melting profile showed a significant decrease of peak height (h2) from 0.50 to 0.39 W/g and the percentage of the area (P A2) from 50 to 38%, within the storage time ( ≤ 0.05); thus, they were considered to be indicators of oil deterioration. Strong negative correlations of the unstable parameters of DSC with chemical indicators of the oils' oxidative stability (PV, p-AV, TOTOX) were found. For DSC parameters, related to the first peak (h1, A1) and the third peak (h3, A3), changes were statistically not significant within storage ( > 0.05); thus, they can be used as markers of flaxseed oil authenticity. The study demonstrated that X-bar and R control charts could effectively monitor changes in the specific peaks and calculated ratios from the DSC melting profile of fresh and stored flaxseed oils, serving as reliable indicators of oil deterioration.
采用将X-bar和R控制图作为统计控制工具的方法，通过差示扫描量热法（DSC）监测新鲜和储存亚麻籽油的熔化曲线变化。收集了来自五个不同品种的亚麻籽油在储存0、2、4和6个月后的相变熔化曲线。使用去卷积分析程序识别出在约-36、-30、-25和-12°C处的四个峰，该程序能够收集峰温度（T）、峰高（h）、峰面积（A）、面积百分比（P A）以及根据这些参数计算的比率的数据。从熔化曲线的第二个峰获得的控制图显示，在储存时间内，峰高（h2）从0.50 W/g显著降低至0.39 W/g，面积百分比（P A2）从50%降至38%（≤0.05）；因此，它们被认为是油质劣化的指标。发现DSC不稳定参数与油的氧化稳定性化学指标（PV、p-AV、TOTOX）之间存在强负相关。对于与第一个峰（h1、A1）和第三个峰（h3、A3）相关的DSC参数，储存期间的变化在统计学上不显著（>0.05）；因此，它们可用作亚麻籽油真实性的标记。该研究表明，X-bar和R控制图可以有效地监测新鲜和储存亚麻籽油DSC熔化曲线中特定峰和计算比率的变化，作为油质劣化的可靠指标。
