RESUMO
The aims of this study were to extract pectin from rapeseed cake (RSC) by enzymatic hydrolysis using commercial enzymes (Celluclast and Alcalase) and to investigate the effects of different reaction conditions, such as enzymatic hydrolysis time, enzyme-RSC ratio, and Celluclast-Alcalase ratio, on the degradation of RSC and pectin yield. RSC was treated using a combined extraction process that consisted of a fat removal process, enzymatic hydrolysis, and isopropanol/ethanol precipitation. After the fat removal process and enzymatic hydrolysis, defatted-RSC was suitably decomposed, and the loss of liberated reducing sugars was minimized when the hydrolysis condition reached a hydrolysis time of 270 min or an enzyme-RSC ratio of 1:50. Based on these results, various Celluclast-Alcalase ratios were applied. Alcalase led to the destruction of protein-carbohydrate complex in defatted-RSC, whereas Celluclast cleaved some linkages of carbohydrate slightly. As a result, the highest pectin yield was 6.85% at the Celluclast-Alcalase ratio of 1:4.
Assuntos
Brassica rapa/química , Pectinas/química , HidróliseRESUMO
In this study, rapeseed cake (RSC) was used as a source of pectins due to its high carbohydrate content. Different combinations of treatments were applied to investigate the effect of combination processes on the extraction of pectin from RSC. The treatments chosen for combination were a fat removal process (FRP) (solvent extraction using an alcohol-benzene mixture), a chemical treatment (CT) (hydrolysis using 1% hydrochloric acid), and an enzymatic hydrolysis (EH). After the combined processes, pectins were extracted by isopropanol/ethanol precipitation and the residues were analysed by HPLC or an elemental analyser. The pectin yields and galacturonic acid contents were increased by FRP because 72.13% of the total fat was removed; additionally, EH had a similar effect. However, CT decreased the yields because the treatment was too harsh and the galacturonic acid broke down. Pectin yields and galacturonic acid contents were highest in the combination process FRP/EH (6.23% and 64.23%, respectively).
Assuntos
Brassica napus/química , Fracionamento Químico/métodos , Pectinas/isolamento & purificação , Extratos Vegetais/isolamento & purificação , Cromatografia Líquida de Alta Pressão , Hidrólise , Pectinas/química , Extratos Vegetais/análise , Extratos Vegetais/químicaRESUMO
Okara, an organic waste product obtained from soy milk production, was used with copper chloride or sodium borate to formulate new wood preservatives as a substitute for expensive wood preservatives, such as copper-azole-based preservatives and ammoniacal copper quaternary. Before formulating the preservatives, okara was hydrolyzed by enzymes (cellulase, pectinase, and protease) to augment penetration and fix the biocide salts of the preservatives into wood blocks. The preservatives were injected into wood blocks by vacuum pressure to measure the treatability of the preservatives. The treated wood blocks were placed in hot water for 3 d to measure leachability. The treatability and leachability of the preservatives were affected by the type and loading amount of enzymes and the addition of sodium borate into okara-based wood preservative formulations. The treatability and leachability of the preservatives formulated with copper chloride and okara hydrolysates were 63.38 and 3.15%, and those of the preservatives with copper chloride, okara hydrolysates, and sodium borate were 61.47 and 3.32%, respectively. Despite the hot water leaching, wood blocks treated with preservatives formulated with 2% cellulase, pectinase, and protease hydrolyzed okara, CuCl(2), and sodium borate showed only 1.98% average weight loss against Fomitopsis palustris over 12 weeks. Microscopic observation revealed how okara-based preservatives work in wood blocks. Okara has potential as a raw material for cost-effective and environmentally friendly wood preservatives.
Assuntos
Antifúngicos/toxicidade , Boratos/toxicidade , Cobre/toxicidade , Desinfetantes/toxicidade , Resíduos Industriais , Madeira/ultraestrutura , Azóis/toxicidade , Coriolaceae/efeitos dos fármacos , Indústria Alimentícia , Química Verde , Hidrólise , Gerenciamento de ResíduosRESUMO
Novel biocides, such as copper azole (CuAz) and ammoniacal copper quaternary (ACQ), are extensively used as substitutes for chromate copper arsenate (CCA) in wood preservation. However, the expense of these biocides has necessitated the development of cost-effective and environmentally friendly wood preservatives. This study was conducted to investigate the effectiveness against decaying fungi of the preservatives formulated with enzymatic-hydrolyzed okara (OK), which is an organic waste produced from the manufacture of tofu, CuCl(2) (CC) and/or Na(2)B(4)O(7).10H(2)O (B). With the addition of NH(4)OH as a dissociating agent, the addition of OK facilitated the target retention of most of the OK/CC and OK/CC/B preservative formulations in wood blocks. The OK-based wood preservatives (OK-WPs) were stable against hot-water leaching. When compared with control and CC-treated wood blocks, the leached wood blocks treated with OK/CC and OK/CC/B formulations showed excellent decay resistance against both Postia placenta and Gloeophyllum trabeum, especially when OK was hydrolyzed by Celluclast at a loading level of 0.1 ml/g. Scanning electron microscopy (SEM) and SEM-energy dispersive X-ray (SEM-EDX) spectrometry analyses demonstrated that preservative complexes, such as OK-CC and OK-CC-B, existed in the wood blocks treated with OK/CC and OK/CC/B formulations. This study results support the potential application of OK-WPs as environmentally friendly wood preservatives capable of replacing CuAz and ACQ.