Biochemical and physicochemical properties of shrimp (Pandalus borealis) compounds after compact filter press process

Abstract

BackgroundMost of the shrimp side streams are discarded due to the lack of appropriate processing techniques/methodology for their utilization, which is not only a loss of potentially valuable compounds, but also leads to environmental pollution. The study aimed to employ a mechanical filter press to separate the liquid called press juice (PJ) and the solid named press cake (PC) fraction from shrimp head and shell (H&S).ResultsThe proximate composition was performed, including amino acids analysis, protein content, fatty acids, and the main volatile compounds. In the whole shrimp, the average values of protein, lipid, dry matter, and ash content were recorded at 14.7%, 2.9%, 21.1% and 4.8%, respectively. The protein percentage reached to 10.1% in head and shell, indicating considerable amount of protein leftover in the shrimp side streams (p < 0.05). The major PUFAs in whole shrimps' sample were EPA (8.8%) and DHA (7.8%). Furthermore, the values of EPA and DHA showed nearly two‐folded increase after peeling and filter pressing, press cake sample. Total amino acids in the whole shrimp, head and shell, press juice and press cake samples were found to be 94.6, 67.7, 22.2, and 76.6 mg/g, respectively. From the nutritional point of view, non‐essential amino acids (NEAAs) represented higher values (13.2%–56.9%) compared to essential amino acids (EAAs) (9.0%–37.6%). The major components of 5′‐neucleoitides in whole shrimp sample were in order of GDP> > HYP > IMP> > AMP > ADP with values of 684.4, 293.6, 201.4, 25.6 and 16.2 μg/g sample, while no INO, GMP and GTP were detected. EUC (g MSC/100 g) was recorded as 0.63, 0.07 for whole shrimp and head and shell samples and 0,015 for press juice sample, which indicates a significant drop from the shrimp raw material toward the side streams. Most volatile compounds belonged to alkenes followed by alkanes groups.ConclusionThis work showed the possibility to employ the filter press machine to obtain press juice and press cake from shrimp head and shell, after peeling processing. The fractions present an interesting nutritional composition and value.This article is protected by copyright. All rights reserved.