Majewski Michał, Lebiedzińska Anna
Rocz Panstw Zakl Hig. 2014;65(2):101-5.
A rich and natural source of readily assimilated dietary protein together with invaluable vitamins and minerals are fish, particularly the saltwater species. The quality of any given foodstuff is determined by its nutritional value, which in turn depends on the food type and methods used for manufacture, processing and storage. Many fish products contain fewer water soluble vitamins than the source foodstuff as a result of using various technologies during food processing, such as smoking or deep freezing, where vitamins are often either degraded or leached out. In the case of niacin it is relatively easy to make good such losses by eating niacin-rich foods or by taking dietary supplements e.g. the essential amino acid L-tryptophan.
To determine niacin content in sea fish that are commonly available on the Polish market and to assess whether this dietary source is sufficient to satisfy the RDA requirements for various age groups of selected subjects living in Poland.
Niacin levels were measured firstly in 10 saltwater fish species together with butterfish and Norwegian salmon that formed a separate group. Altogether, 15 types of fish products were analysed in all. They consisted of smoked fish: whitefish, butterfish, sprat, trout, herring (kippers) and mackerel, and frozen fish: butterfish, Norwegian salmon, sole, grenadier and panga. Each product was measured as ten replicates, thus in total 150 analyses were performed. A microbiologically-based method was used for the niacin determination, with enzyme hydrolysis by 40 mg papain and diastase on a 2 g sample (according to the AOAC procedure) to release the free form from the bioavailable form that is bound to NAD and NADP.
The most plentiful sources of niacin were found in smoked fish with the highest amounts in butterfish, after warm temperature smoking, and in mackerel; respectively 9.03 and 8.90 mg/100 g. Such 100 g portions of smoked fish are a good dietary source of niacin, in that for men and women above 19 years of age, they constitute respectively 22% - 56% and 25% - 64% of the RDA (Recommended Daily Allowance). The highest levels of niacin in frozen fish were found in butterfish and Norwegian salmon; respectively 8.05 and 5.75 mg/100 g which in turn represent respectively 10% - 50% and 11% - 56% of the RDA in men and women aged above 19 years.
Niacin concentrations varied according to fish species. The richest dietary sources were smoked fish consisting of butterfish, after warm temperature smoking, and mackerel. In frozen fish, butterfish and Norwegian salmon had the highest niacin amounts. A 100 g serving of such sea fish can, to quite a large extent, satisfy the adult RDA.
鱼类，尤其是海水鱼，是易于吸收的膳食蛋白质以及宝贵的维生素和矿物质的丰富天然来源。任何一种给定食品的质量都由其营养价值决定，而营养价值又取决于食物类型以及制造、加工和储存所使用的方法。由于在食品加工过程中使用了各种技术，如烟熏或深度冷冻，许多鱼产品中水溶性维生素的含量比源食品少，在这些过程中维生素常常会降解或被浸出。就烟酸而言，通过食用富含烟酸的食物或服用膳食补充剂，如必需氨基酸L-色氨酸，相对容易弥补此类损失。
测定波兰市场上常见海鱼中的烟酸含量，并评估这种膳食来源是否足以满足波兰特定年龄段不同人群的推荐膳食摄入量（RDA）要求。
首先测定了10种海水鱼以及单独归为一组的白姑鱼和挪威三文鱼中的烟酸含量。总共分析了15种鱼产品。它们包括烟熏鱼：白鱼、白姑鱼、黍鲱、鳟鱼、鲱鱼（腌鱼）和鲭鱼，以及冷冻鱼：白姑鱼、挪威三文鱼、鳎鱼、长尾鳕和淡水白鲳。每种产品测量10次重复，因此总共进行了150次分析。采用基于微生物学的方法测定烟酸含量，用40毫克木瓜蛋白酶和淀粉酶对2克样品进行酶水解（根据美国官方分析化学师协会程序），以从与烟酰胺腺嘌呤二核苷酸（NAD）和烟酰胺腺嘌呤二核苷酸磷酸（NADP）结合的生物可利用形式中释放出游离形式。
在烟熏鱼中发现烟酸含量最丰富，经温熏后的白姑鱼和鲭鱼含量最高，分别为9.03毫克/100克和8.90毫克/100克。这样100克的烟熏鱼是烟酸的良好膳食来源，对于19岁以上的男性和女性，它们分别占推荐膳食摄入量的22% - 56%和25% - 64%。冷冻鱼中烟酸含量最高的是白姑鱼和挪威三文鱼，分别为8.05毫克/100克和5.75毫克/100克，这对于19岁以上的男性和女性分别占推荐膳食摄入量的10% - 50%和11% - 56%。
烟酸浓度因鱼的种类而异。最丰富的膳食来源是经温熏后的白姑鱼和鲭鱼组成的烟熏鱼。在冷冻鱼中，白姑鱼和挪威三文鱼的烟酸含量最高。100克这样的海鱼在很大程度上可以满足成年人的推荐膳食摄入量。
