Utilizing biosynthesized nano-enhanced laser-induced breakdown spectroscopy for proteins estimation in canned tuna

Abstract

Proteins in canned tuna fish were assessed using laser-induced breakdown spectroscopy (LIBS) technique. Biosynthesized nanoparticles (BS-NPs) have been used to enhance the emission intensity of the spectral lines in LIBS spectra of tuna fish samples. Silver nanoparticles (Ag NPs) were biosynthesized in a simple and cheap way using potatoes (Solanum tuberosum) extract. Three cans from each of three different brands of high-, medium- and low-quality canned tuna fish were investigated. Six samples, pressed in small tablets, have been taken from each can. Half the number of samples was used for conventional LIBS measurements, while the other half was used for nano-enhanced LIBS. An enhancement of more than three times has been obtained in the spectral lines intensity of the biosynthesized nano-enhanced LIBS (BS-NELIBS) spectra. The intensities of CN and C2 molecular bands (at 388.34, and 516.52 nm respectively) in the obtained spectra are related to the proteins' content, and consequently to the quality of the different tuna fish brands. The conventionally estimated proteins' content in the three investigated brands of canned tuna validated the results obtained via BS-NELIBS. Quantitative estimation of the proteins in tuna samples was available using the correlation between the protein percentage measured conventionally and CN intensity in the relevant LIBS spectra. BS-NELIBS has been proven to be easy, fast and reliable analytical technique for the qualitative and quantitative estimation of the proteins in canned tuna fish. This method is feasibly applicable in the production monitoring of canned foods containing proteins.