Vpliv pogojev skladiščenja na vsebnost ekstraktivov v skorji bele jelke

Hrovatič, Peter (author), Vek, Viljem (mentor), Poljanšek, Ida (comentor)

Koncept krožnega gospodarstva obravnava ostanke proizvodnih procesov kot pomembno surovino za proizvodnjo novih izdelkov z dodano vrednostjo. V tem kontekstu je skorja, ostanek v lesnopredelovalni industriji, že prepoznana kot surovina za ekstrakcijo naravnih antioksidantov, ki se uporabljajo v prehranskih dopolnilih. Ustrezna manipulacija s skorjo pred ekstrakcijo je pomembna za zagotavljanje kakovostnih ekstraktov. Z MSc nalogo smo preučili vpliv priprave in načina hranjenja skorje na vsebnost ekstraktivov in polifenolov v skorji. Raziskavo smo osnovali na skorji kočevske bele jelke (Abies alba Mill.), vzorce skorje smo naravno starali na dveh testnih lokacijah. Z monitoringom sprememb v kemijski sestavi ekstraktivov smo analizirali vpliv velikosti delcev skorje, časa odvzema skorje in pogojev skladiščenja na vsebnost ekstraktivov in polifenolov v skorji. Monitoring je trajal eno leto, meritve smo izvajali mesečno. Vzorce skorje smo ekstrahirali z vodo, kakovost ekstraktov smo nato kemijsko ovrednotili z gravimetrijo, spektrofotometrijo in kromatografijo. Analizirali smo tudi vpliv termične obdelave na vsebnost ekstraktivov in polifenolov v jelovi skorji. Rezultati meritev so pokazali, da na vsebnost ekstraktivov močno vplivata velikost delcev biomase in prostor, kjer skorjo skladiščimo. Vsebnost ekstraktivov v skorji se je v največji meri ohranila takrat, ko smo skorjo neobdelano/nepredelano skladiščili v temnem in pokritem prostoru. Rezultati kažejo, da je skorjo z debel smiselno odstrani čim kasneje, torej tik pred ekstrakcijo. Termična obdelava v določeni meri negativno vpliva na vsebnost polifenolov v skorji, vendar je ta faza obdelave nujna in jo v procesu priprave biomase za transport ne moremo izključiti. Jelovo skorjo lahko ustrezno osušimo s krajšo termično obdelavo ob uporabi milejših sušilniških programov.

• Language: Slovenian
• Keywords: bela jelka, les, skorja, ekstraktivi
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: BF - Biotechnical Faculty
• Publisher: [P. Hrovatič]
• Year: 2024
• PID: 20.500.12556/RUL-161835
• UDC: 630*813.2
• COBISS.SI-ID: 207575555
• Publication date in RUL: 15.09.2024

Secondary language

• Language: English
• Title: Influence of storage conditions on the extract content in silver fir bark

Abstract

The concept of the circular economy regards the residues of production processes as an important raw material for the manufacture of new products with added value. In this context, bark is a residue from the wood industry that is already recognized as a raw material for the extraction of natural antioxidants used in dietary supplements. Proper treatment of the biomass prior to extraction is important to ensure adequate quality of the extracts. As part of the master's thesis, the influence of the treatment and storage of bark on the content of extractives and polyphenols was investigated. The bark of silver fir (Abies alba Mill.) from kočevska region was exposed to weathering at two test sites. The influence of the bark particle size, the time of debarking and the storage conditions of the bark on the content of extractives and polyphenols was analyzed by observing the changes in the chemical composition. The monitoring period was one year and the measurements were carried out monthly. The bark samples were extracted with water and the quality of the extracts was evaluated by chemical analysis. The influence of the thermal treatment of the bark on the content of extractives was also investigated. The results showed that the content of extractives is strongly influenced by the bark particle size and the storage location of the bark. The extractives content was best preserved when the bark was stored unprocessed in a dark and covered place. We found that the bark should be removed from the log shortly before extraction. Silver fir bark must be sufficiently dried, although shorter thermal treatment and gentler drying programs can be used to preserve the polyphenols in the biomass.

• Keywords: Silver fir, wood, bark, extractives