Utilization of Small Size Bolti (<i>Talibia nilotica</i>) and Sardine (<i>Sardina pilchardus</i>) Fish in Preparing Canned Weaning Food Purees

Utilize small size of bolti and sardine fish in preparing fish based weaning foods rich in protein, essential amino acids, fat high in omega 3 fatty acids, minerals and vitamins was investigated. The proximate composition, nutritional value, physical and sensorial properties were evaluated, The results of the chemical composition showed that the moisture content of fish based weaning food purees ranged from 67.73% to 72.05%. On dry weight basis, the five prepared formulations considered rich in protein (37.39% - 44.86%), fat (26.55% - 30.43%), ash (6.53% - 12.23%) and low in carbohydrates (20.70% - 22.18%). Using fish bones with muscles in preparing weaning food puree caused a marked rise in its content of Ca, P, Fe, and Zn levels especially in purees formulated from bolti. Weaning food purees containing sardine fish rich, in fat, were higher in vitamin A and D than those formulated from bolti one. Palmitic acid (C16:0), stearic acid (C18:0), and myristic acid (C14:0) represented the major saturated fatty acids in the prepared formulations. Weaning food purees containing sardine fish had relatively higher levels of sulfur-containing amino acids and slight lower values of lysine, alanine and glycine than these including bolti fish. The In vitro protein digestibility index (IVPDI) of the different formulations was found to be 100%. The visual colour of such products can be described as yellowish. Except hardness, the other texture characteristics;cohesiveness, springiness, gumminess, and chewiness of the weaning food purees did not significantly change. The children’s mothers accepted the appearance, flavor, and mouth feel of all weaning food purees prepared in this study.

Ontogenetic changes in digestive enzyme activities and the amino acid profile of starry flounder Platichthys stellatus

Ontogenetic changes in digestive enzyme activities and the amino acid(AA) profile of starry flounder,Platichthys stellatus,were investigated and limiting amino acids were estimated compared with the essential AA profile between larvae and live food to clarify starry flounder larval nutritional requirements.Larvae were collected at the egg stage and 0,2,4,7,12,17,24 days after hatching(DAH)for analysis.Larvae grew from 1.91 mm at hatching to 12.13 mm at 24 DAH.Trypsin and chymotrypsin activities changed slightly by 4 DAH and then increased significantly 4 DAH.Pepsin activity increased sharply beginning 17 DAH.Lipase activity increased significantly 4 DAH and increased progressively with larval growth.Amylase activity was also detected in newly hatched larvae and increased 7 DAH followed by a gradual decrease.High free amino acid(FAA) content was detected in starry flounder eggs(110.72mg/g dry weight).Total FAA content dropped to 43.29 mg/g in 4-DAH larvae and then decreased gradually to 13.74 mg/g in 24-DAH larvae.Most FAAs(except lysine and methionine) decreased >50%in 4-DAH larvae compared with those in eggs and then decreased to the lowest values in 24-DAH larvae.Changes in the protein amino acid(PAA) profile were much milder than those observed for FAAs.Most PAAs increased gradually during larval development,except lysine and phenylalanine.The percentages of free threonine,valine,isoleucine,and leucine decreased until the end of the trial,whereas the protein forms of these four AAs followed the opposite trend.A comparison of the essential AA composition of live food(rotifers,Artemia nauplii,and Artemia metanauplii) and larvae suggested that methionine was potentially the first limiting AA.These results may help develop starry flounder larviculture methods by solving the AA imbalance in live food.Moreover,the increased digestive enzyme activities indicate the possibility of introducing artificial compound feed.