靖海湾条斑紫菜的营养及鲜味评价

以不同收割期的靖海湾条斑紫菜(Pyropia yezoensis)为研究对象，对比分析营养价值并评价其鲜味。通过测定基本营养成分、无机元素组成和氨基酸组成，分析其营养学特征，通过测定游离氨基酸与呈味核苷酸组成，进而计算滋味活性值(Taste active value, TAV)与味精当量(Equivalent umami concentration, EUC)。结果显示，靖海湾条斑紫菜蛋白质含量丰富，头水和二水紫菜的蛋白含量均在49%以上，显著高于四水和六水紫菜(P<0.05)。不同收割期条斑紫菜的脂肪含量较低，均小于1.1%。常量元素中P含量最低，K含量最高，约为2.59×104~5.52×104 mg/kg；微量元素以Fe含量最高，Zn次之，Co最低；Pb含量明显低于GB 2762-2017的限量要求。头水、二水紫菜与四水、六水紫菜的必需氨基酸及氨基酸总量间存在显著差异(P<0.05)。游离谷氨酸和次黄嘌呤核苷酸对条斑紫菜的鲜味起主要贡献作用，头水、二水、四水和六水紫菜的EUC(以干基计)依次降低，分别为239.71、190.03、108.05和51.56 g MSG/100 g。靖海湾条斑紫菜具有较高的营养价值，且收割前期的靖海湾条斑紫菜鲜味度较高，可作为开发调味品的原料。

Nutritional Analysis and Umami Assessment of Pyropia yezoensis from Jing Bay

Pyropia yezoensis at different harvest times were obtained from Jing Bay, and its nutritional and umami characteristics were analyzed. Crude protein, crude fat, ash, inorganic elements, and amino acid composition were determined to analyze its nutritional characteristics. Free amino acids and flavor nucleotides were determined to calculate the taste active value (TAV) and equivalent umami concentration (EUC), which indicated the umami of P. yezoensis. The results showed that P. yezoensis from Jing Bay had high protein and low fat content. The protein content exceeded 49% in the first and second harvest, indicating that the P. yezoensis had higher nutritional value in the early stage of the harvest. The K content was the highest among the constant elements, while the P content was the lowest. Fe content was the highest among the trace elements; Zn content was higher, and Co content was the lowest. Pb content was significantly lower than the limited requirements of GB 2762-2017. There were significant differences between P. yezoensis from the first, second harvest and the fourth, sixth harvest in terms of essential and total amino acid content (P<0.05). Glutamic acid and hypoxanthine nucleotide played a major role in the umami contribution; the Equivalent umami concentration (in dry basis) of P. yezoensis in the first, second, fourth, and sixth harvests was 239.71, 190.03, 108.05, and 51.56 g MSG/100 g, respectively. P. yezoensis from Jing Bay has high nutritional values and desirable umami characteristics in the early stage of harvest, and thus, has great market potential.