Determination of Total Nucleotides, Nitrogenous Bases and Degradation By-Products with Respect to Various Processing and Preservation Techniques for Alaska Pollock (Gadus chalcogrammus) and Yellowfin Sole (Limanada aspera)

• Main Author: Nelson, Kevin A.
• Other Authors: DeWitt, Christina M., Park, Jae W., Penner, Michael H., Chaplen, Frank W. R., Food Science and Technology
• Format: Master Thesis
• Language: English
• Published: Oregon State University
• Subjects: alaska pollock; Alaska
• Online Access: https://ir.library.oregonstate.edu/concern/graduate_thesis_or_dissertations/jd4733902

The primary goal of this research was to determine the concentration and composition of nucleotides, as nucleoside monophosphates and nucleobases, in the underutilized reproductive organs (milt and roe) of Alaska pollock (Gadus chalcogrammus) and yellowfin sole (Limanda aspera). Changes in concentrations of these nucleotides and nucleotide analogs were observed with respect to various storage and processing techniques. Samples were freeze-dried (-40°C), dessicated (70°C) and oven dried in laboratory ovens at two temperatures (100°C and 120°C). Several extraction/digestion techniques were employed to evaluate total nucleotides present. DNA extracts were analyzed for total nucleotide monophosphates and nucleotide composition of the DNA extract. Methods for extracting total DNA from reproductive tissues from pollock were evaluated using various chemical techniques including acid digestion, phenol-chloroform extraction and QIAGEN® extractions kits. Once extracted, DNA was digested into nucleotide monomers (deoxyadenosine monophosphate (dAMP), deoxyguanosine monophosphate (dGMP), deoxycytidine monophosphate (dCMP) and thymidine monophosphate (TMP)) using an enzymatic (endonuclease) digestion. In a different analysis, total nucleobases and nucleobase composition as purine and pyrimidine bases (cytosine, guanine, thymine, adenine, uracil, hypoxanthine and xanthine) were also determined; these results were used to assess total DNA, RNA and free nucleotides in dried milt meal. Quantification of the nucleotides was achieved using a reverse-phase high performance liquid chromatography (RP-HPLC) system. Degradation by-products of adenosine monophosphate (as adenosine monophosphate (AMP), inosine monophosphate (IMP), inosine and hypoxanthine) were also determined via HPLC after perchloric acid digestion. This knowledge will serve as a basis of determining the feasibility of creating a consistent, cost-effective source of nucleotide or nucleotide analogs for potential use in the formulation of aquaculture feed, nutraceuticals ...