High hydrostatic pressure (HHP) treatments are trending as “green” stabilization and extraction process. The extraction of B-phycoerythrin from microalgae is getting more and more interest due to its numerous potentialities in foods, cosmetics and medicine. Thus, the effects of high pressure on the structural characteristics of B-phycoerythrin extracted from Porphyridium cruentum are explored in this paper.

Spectrophotometric methods allowed to measure B-phycoerythrin content (UV–visible) and gave an indication on the protein structure (fluorescence). Micro-DSC analysis and electrophoresis complemented this structural investigation for all the protein fractions of P. cruentum extracts.

Applying high hydrostatic pressure treatments up to 300 MPa during 5 min had no significant effect on B-phycoerythrin content and structure in P. cruentum extracts. Nevertheless, conformational changes of the protein are suggested by fluorescence yield decrease at 400 MPa, and protein aggregation of B-phycoerythrin, observed by Micro-DSC and electrophoresis, occurred at 500 MPa.

Industrial relevance

The HHP process is an emerging technology for the microbiological stability of various food matrices, including the proteins of microalgae as natural colorant. The target pressure to stabilize is around 400 MPa. High hydrostatic pressure can be used on P. cruentum extracts up to 300 MPa without any change in protein structure, as the threshold of protein aggregation is observed at 400 MPa. The observed changes of the proteins structure after applying HHP above 400 MPa can have a strong impact at macroscopic scale on the food matrices: increase of turbidity, change of texture, stability of emulsion.

中文翻译：

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高静水压力对十字花紫菜提取物中可溶性蛋白组分的结构的影响

高静水压（HHP）处理正在成为“绿色”稳定化和提取过程的趋势。由于其在食品，化妆品和药品中的巨大潜力，从微藻中提取B-藻红蛋白越来越受到关注。因此，本文探讨了高压对从卟啉卟啉菌中提取的B-藻红蛋白结构特征的影响。

分光光度法可以测量B-藻红蛋白含量（紫外线可见），并提供蛋白质结构的指示（荧光）。Micro-DSC分析和电泳补充了苦瓜提取物所有蛋白质部分的结构研究。

在5分钟内施加高达300 MPa的高静水压力处理对苦瓜提取物中的B-藻红蛋白含量和结构没有显着影响。然而，蛋白质的构象变化通过400 MPa下的荧光产率降低而暗示，并且通过Micro-DSC和电泳观察到的B-藻红蛋白的蛋白质聚集在500 MPa下发生。

行业相关性

HHP工艺是使各种食品基质（包括作为天然着色剂的微藻蛋白）具有微生物稳定性的新兴技术。稳定的目标压力约为400 MPa。由于在400 MPa处观察到蛋白质聚集的阈值，因此可以在高达300 MPa的菊科植物提取物中使用高静水压力，而不会改变蛋白质结构。施加高于400 MPa的HHP后，观察到的蛋白质结构变化在宏观上会对食品基质产生强烈影响：浊度增加，质地变化，乳液稳定性。