Efektiivne kalajääkide kasutamine uudsete toormaterjalide saamiseks, mida on võimalik kasutada nii kanga kui haavakatete valmistamiseks

Abstract

Kala- ja koorikloomajäägid sisaldavad väärtuslikke biopolümeere, millest käesolevas projektis käsitletakse kollageeni ja kitiini. Projekti eesmärgiks oli välja selgitada, kas on võimalik kala- ja koorikloomajääkidest saada kvaliteetset toorainet, mida on võimalik kasutada haavakatete ja nahalaadse tekstiili tootmiseks. Kalajääkidest eraldasime želatiini (kollageenne biopolümeer), mille omadusi hinnati haavakattematerjali ning nahalaadse tekstiili valmistamise seisukohast. Samuti andsime hinnangu vähijääkidest eraldatud kitiini ja sellest toodetud kitosaani kvaliteedile. Projektis osalesid juhtorganisatsioonina Eesti Maaülikool ning partneritena Tartu Ülikool ning Gelatex Technologies OÜ; samuti tegime koostööd Eesti kalatöötlemisettevõtetega projektiks vajalike kalajääkide kogumiseks. Eesti Maaülikooli töörühm (projekti vastutav täitja Anu Kisand; Kairi Käiro, Maidu Silm, Rihard Reissaar; nõustajana prof. Rajeev Bhat) viis läbi kalajääkidest toormaterjalide eraldamine, Tartu Ülikooli Farmaatsia Instituudi teadurid ja üliõpilased Karin Kogermanni juhtimisel viisid läbi saadud toormaterjalide karakteriseerimise ning neist toormaterjalidest haavakattematerjalide valmistamisega seotud uuringud, Gelatex Technologies OÜ meeskond Märt- Erik Martensi juhtimisel viis läbi želatiinist nahalaadse tekstiilmaterjali valmistamisega seotud uuringud. Toormaterjalipartiide valmistamine Eesti Maaülikoolis toimus tihedas koostöös projektipartneritega: tuginedes partnerite tagasisidele varasemate partiide karakteriseerimis- ja töötlemistulemuste kohta optimeeriti järgnevate partiide valmistamise meetodeid. Käesolevas projekti lõpparuandes käsitleme nii kala- ja koorikloomajääkidest toormaterjalide valmistamise etappe kui ka saadud materjalide omadusi ning kasutatavust haavakatete ja nahalaadse kanga tootmisel. Loodame, et käesoleva projekti tulemused julgustavad bio- ning ringmajandusest huvitatud osapooli kaasa mõtlema kalajäätmete väärindamise edendamise suunas. Projekti läbiviimiseks vajaliku toetuse eraldas Maaeluministeerium Euroopa Merendus- ja Kalandusfondi rakenduskava 2014-2020 meetme 1.1 „Kalapüügi innovatsioonitoetus” vahenditest rakendusüksuse PRIA kaudu. Projekt kestis 29.10.2019-15.02.2022.

Utilization of fish waste for production of raw materials applicable in wound dressing and textile industry

Fish processing industry results in considerable amount of waste materials as processing residuals. Insted of discarding, alternative use and refining of these waste materials would enhance the gross gain from the raw material, and, simultaneously, reduce the cost on waste treatment. Among other constituents, fish industry processing residuals contain valuable biopolymers like polypeptide collagen and polysaccharide chitin, thus they could serve as source materials for gelatin and chitosan production. Gelatin is derived from collagen and can be used in multiple applications including nanomaterials, pharmacy, cosmetics, food industry etc. For example, electrospun nanofiber mats with antibacterial agents as drug delivery systems provide opportunities for the eradication of bacterial infections as well as wound healing (Preem et al, 2019). Gelatin is one of the most important natural biomaterials for the design and construction of electrospun nanofiber-based dressings, due to its excellent biocompatibility and biodegradability, and great exudate-absorbing capacity (Li et al., 2022). As another example of gelatine application, fabrication of leather-like textile based on gelatine nanofiber mats can be considered as environmentally sustainable alternative to direct skin processing involving toxic substances. Chitin, in turn, is a source material for production of chitosan, a compund with variety of emerging commercial applications in material industry, agriculture, biomedicin, pollution treatment etc. The aim of the project was to elucidate the potential of selected residual byproducts of local fish industry for preparation of high-quality gelatin suitable for production of nanofiber materials for wound dressing and leather-like textile applications. Additionally, we conducted a minor study on chitin purification from crayfish shells, and subsequent chitin processing for chitosan yield. In the course of current project we produced fish gelatin from the skin of freshwater bream (Abramis brama), originated from Lake Peipsi, Estonia. The bream skins were obtained as industrial fish filleting residues. Gelatin production parameters were optimized to gain high-quality gelatin suitable for production of nanofibers for both wound dressing application and production of textile material. Both the produced gelatin and resultant nanofiber materials were characterized for physical and chemical properties, while wound dressing material was additionally tested for pharmaceutical requirements. 62 Business card pockets were crafted as an example of an accessory made of leather-like gelatin-based textile and specimens of wound patch were fabricated to illustrate the potential wound dressing application of the fish gelatin produced from residual waste of Estonian fish industry. Current report in Estonian presents the overview of the project outcomes. Detailed results will be published in international scientific journals. In Appendix of the report, an overview of the alternative applications and future scope and of the fish gelatin is presented in English. The project was conducted by Estonian University of Life Sciences in cooperation with project partners University of Tartu (Institute of Pharmacy) and Gelatex Technologies OÜ. Project implementation period was 29.10.2019-15.02.2022. The project was funded by European Maritime and Fisheries Fund (EMFF) for 2014–2020.