东山湾海马齿嫩茎和嫩叶的营养成分分析与评价

Analysis and evaluation of nutritional components in spears and leaflets of Sesuvium portulacastrum in Dongshan Bay

[目的]分析福建省东山湾鱼类网箱养殖区的海马齿(Sesuvium portulacastrum)可食用部位的营养成分与品质.[方法]采用国标法检测海马齿嫩茎、嫩叶和嫩茎叶的主要营养成分、维生素含量和氨基酸组成,采用氨基酸评分(AAS)、氨基酸比值系数分(SRCAA)和必需氨基酸指数(EAAI)进行氨基酸评价.[结果]海马齿嫩茎叶的水分、蛋白质、可溶性糖、粗灰分和粗纤维质量分数分别为90.87%,8.75%,3.29%,2.72%和1.18%,嫩茎的粗灰分和粗纤维质量分数显著高于嫩叶(P<0.05),而嫩叶的水分和蛋白质质量分数显著高于嫩茎(P<0.05).海马齿嫩茎叶的维生素A、维生素B_(2)、维生素C和β-胡萝卜素质量分数分别为0.028,0.049,10.992和1.090 mg/100 g,其在嫩叶中的质量分数分别是嫩茎中的3.27,2.31,2.05和7.14倍.海马齿嫩茎和嫩叶均能测出17种氨基酸,以谷氨酸质量分数最高,而胱氨酸质量分数最低;嫩茎叶的总氨基酸质量分数为1.241%,必需氨基酸、药用氨基酸和甜味氨基酸分别占氨基酸总质量的35%,63%和31%;除脯氨酸、胱氨酸和甲硫氨酸外,嫩叶的14种氨基酸质量分数均显著高于嫩茎(P<0.05).氨基酸评价结果显示,海马齿各部位氨基酸种类齐全,比例分配良好,蛋白质营养价值高,嫩茎的SRCAA和EAAI均高于嫩叶.[结论]经比较,海马齿的营养价值不亚于商业化海水蔬菜北美海蓬子(Salicornia bigelovii)以及福建省常见食用海藻兼鲍饵料如龙须菜(Gracilaria lemaneiformis)和海带(Laminaria japonica),其含有更多的蛋白质和粗纤维,且SRCAA和EAAI评分更高,可为海马齿作为新型海水蔬菜、鲍饵料开发利用以及“鱼菜共生”养殖模式的推广提供参考.

[Objective] Sesuvium portulacastrum is an ideal restoration plant for alleviating eutrophication problems in coastal mariculture areas.In the process of practical application and promotion,how to further utilize the harvested S.portulacastrum has become a pressing issue that needs to be addressed.The nutritional value of S.portulacastrum as vegetables and bait requires further in-depth research,especially for the nutritional composition and quality of the edible parts of S.portulacastrum in the fish cage aquaculture area of Dongshan Bay in Fujian Province,which has been rarely reported.[Methods] The samples were collected in October 2016 from floating beds of S.portulacastrum around the fish cage of Sciaenops ocellatus in Dongshan Bay.Each sample was set up in three replicates,with an approximate fresh weight of 300 g.The main nutritional components,vitamin content and amino acid composition of the spears,leaflets,and spears and leaflets of S.portulacastrum were determined using the national standard method.Amino acid evaluation was conducted using the methods of amino acid score(AAS),score of ratio coefficient of amino acid(SRCAA),and essential amino acid index(EAAI).[Results] The water,protein,soluble sugar,crude ash and crude fiber mass fractions of spears and leaflets of S.portulacastrum were 90.87%,8.75%,3.29%,2.72% and 1.18%,respectively.The crude ash and crude fiber contents of spears were significantly higher than those of leaflets(P<0.05),while the water and protein contents of leaflets were significantly higher than those of spears(P<0.05).Vitamin A,vitamin B_(2),vitamin C,and β-carotene mass fractions of spears and leaflets were 0.028,0.049,10.992 and 1.090 mg/100 g,respectively,and those mass fractions in leaflets were 3.27,2.31,2.05 and 7.14 times as those in spears,respectively.17 kinds of amino acids were detected in both spears and leaflets of S.portulacastrum,with the highest content of glutamic acid and the lowest content of cystine.Moreover,the total amino acid mass fraction of spears and leaflets was 1.241%,and essential amino acids,medicinal amino acids and sweet amino acids accounted for 35%,63% and 31% of the total amino acids,respectively.Except for proline,cystine and methionine,the contents of 14 kinds of amino acids in leaflets were significantly higher than those in spears(P<0.05).The amino acid evaluation results showed that the amino acid types in various parts of S.portulacastrum were complete and well configured,with high protein nutritional value,and the SRCAA and EAAI of spears were higher than those of leaflets.The nutritional value of S.portulacastrum was no less than that of commercial seawater vegetable Salicornia bigelovii,as well as common edible seaweed and abalone bait in Fujian Province,such as Gracilaria lemaneiformis and Laminaria japonica,and it contained more protein and crude fiber,and had higher SRCAA and EAAI.[Conclusion] The spears of S.portulacastrum in Dongshan Bay exhibit higher crude fiber,crude ash,proline and cystine contents compared to leaflets.Conversely,leaflets display higher water content,protein,soluble sugars,vitamins,and contents of the other 15 kinds of amino acids.The essential amino acid composition of S.portulacastrum is reasonable,and it is rich in delicious amino acids and medicinal amino acids which carry important physiological effects.The EAAI evaluation results show that S.portulacastrum can serve as a high-quality protein source for both humans and abalones.In comparison,the nutritional value of S.portulacastrum is no less than that of S.bigelovii and G.lemaneiformis.These research findings provide valuable references for the development and utilization of S.portulacastrum as a new type of marine vegetable,abalone bait,and for promoting a symbiotic ecological breeding model for fish and vegetables.