Characteristics Of Fish Protein Powder Prepared From Snakehead (Channa Striata) Raside On Specialised Lipid Diet
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Date
2016-03
Authors
Tan, Bee Hooi
Journal Title
Journal ISSN
Volume Title
Publisher
Universiti Sains Malaysia
Abstract
Specially-fed Snakeheads (Channa striata) are snakehead fishes fed with
diets high in lipids sourced from fish and soybean which have been shown to
improve their reproduction efficiency. The objective of this study was to prepare
specially-fed protein powder (SFPP) from these snakehead fish and evaluate it. To
achieve this objective, a method has to be developed for the preparation of such
powders. Therefore, this study was divided into two phases. As the supply of
specially-fed Snakeheads was scarce, only commercial snakehead was utilised
during phase I to develop preparation methods for whole fillet powder (WFP) and
snakehead protein powder (HPP). Effects of freezing treatments (direct freezing,
freezing with water or no freezing) before filleting on fillet harvesting yield were
also investigated. To prepare WFP, after freezing treatments, fish were filleted,
minced and oven dried. However, to prepare HPP, minced fillet were heated with
water at 85 ºC and the liquid extract was centrifuged to separate fat from protein.
Freeze drying was used to obtain protein powder. Observations showed that fishes
frozen with water yielded significantly higher (p>0.05) yield of fillets. Fish frozen
with water had less slime on their body and were thus easier to handle. HPP and
WFP obtained from fillets harvested from fish frozen with water also displayed
significantly higher protein and ash and generally, most amino acid content were
either significantly higher or not significantly different compared to powders obtained via other freezing treatments. Therefore, preparation method involving
freezing fish with water was chosen as a preparation step to study specially-fed
snakeheads. In phase II, due to material scarcity, focus was solely on the analysis of
SFPP prepared from fillets from specially-fed snakeheads. When compared to
composition of HPP obtained from Phase I, analysis revealed that SFPP contained
higher ratio of desirable essential amino acids, mainly histidine (22.66 %).
Functional properties of SFPP were also inferior to those of egg white powder.
Differential scanning calorimetry analysis of raw unprocessed fish fillet revealed that
extensive protein denaturation had occurred at 54 °C and may have resulted in loss
of functional properties of SFPP. In conclusion, SFPP was successfully prepared
from specially-fed snakehead and was found to contain good levels of amino acids
when compared to HPP prepared from commercial snakeheads. Unfortunately, SFPP
is not suitable to be manipulated for functional purposes. The use of heat to remove
fats from the fish might be the reason for this inferior property.
Description
Keywords
Snakeheads (Channa striata)