但是真空包装的缺点就是真空组的冷却猪肉在贮存过程中呈暗紫红色，并不是呈现自然的红色，但真空消失后，肉仍然能恢复自然地红色。

But the disadvantage of the vacuum packaging was that chilled pork during storage would turn dark purple, not naturally red, however the meat could still remain natural red, after vacuum disappeared.

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维生素A是构成视觉细胞中感受弱光的视紫红质的组成成分，视紫红质是由视蛋白和11-顺-视黄醛组成，与暗视觉有关。

Vitamin A is to create visual cells in order to feel weak light of the composition of rhodopsin, rhodopsin from opsin and 11 - cis - retinal composition, with the dark vision related.

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