תפריט נגישות
ניגודיות עדינהניגודיות גבוהה
מונוכרום
הדגשת קישורים
חסימת אנימציה
פונט קריא
סגור
איפוס הגדרות נגישות
להורדת מודול נגישות חינם תפריט נגישותניגודיות עדינהניגודיות גבוההמונוכרוםהדגשת קישוריםחסימת אנימציהפונט קריאסגוראיפוס הגדרות נגישותלהורדת מודול נגישות חינםDanay, O., MIGAL Galilee Research Institute LTD, Kiryat Shemona, Israel;
Bilbao, C., Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, CA, United States;
McHugh, T., Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, CA, United States
Fungal chitosan was produced from brown Agaricus bisporus, white Agaricus bisporus, and Pleurotus ostreatus mushrooms (commercially known as brown portobello, white protobello, and oyster mushrooms, respectively) by utilizing a classic alkali deacetylation protocol (PI), as well as a new protocol (PII) that involves a freeze-thawing cycle. The new protocol (PII) has led up to a twofold increase in the obtained chitosan's yield, a more efficient deacetylation process that resulted in up to a threefold decrease in its acetylated units, and a whiter color. For instance, using the PII protocol, 1 g of dry Pleurotus ostreatus mushrooms yielded 44.3 mg of chitosan that contained only 14.8% acetylated units, and had a whiteness index of 80.3. For comparison, using the classic PI protocol, 1 g of dry Pleurotus ostreatus mushrooms yielded only 22.4 mg of chitosan with 44.1% acetylated units, and a whiteness index of 75.7. Gel permeation chromatography, FTIR, NMR, UV, elemental analysis, X-ray diffractometry, and thermogravimetric analysis were all used to characterize the prepared fungal chitosan samples and examine their physical properties (viscosity, color, hydrophobicity, and solubility). Microbiological studies have revealed the yielded chitosan samples have demonstrated biological activity against Gram-positive Bacillus subtilis, Gram-negative Escherichia coli bacteria, and Saccharomyces cerevisiae yeast. The prepared fungal-sourced chitosan samples were also compared with the crustacean-sourced commercial chitosan all throughout this paper studies. It can be concluded that the PII protocol allows for the formation of fungal chitosan with quality and properties that do not fall short of those found in the crustacean-sourced chitosan. This study therefore presents an efficient method for the production of non-animal sourced chitosan, which is extremely desired in the food industry because it overcomes the limitations of animal-sourced chitosan and allows to expand this material use. In addition, the presented freeze-thaw cycle technique can also be used to yield and modify other edible hydrocolloids. © 2018 Elsevier Ltd
Postharvest and Food Science Institute, Agricultural Research Organization, The Volcani Center, Rishon LeZion, Israel; Key Laboratory of Agricultural Products Chemical and Biological Processing Technology of Zhejiang Province, School of Biological and Chemical Engineering, Zhejiang University of Science and Technology, Hangzhou, Zhejiang, China; Institute of Biochemistry, Food Science and Nutrition, The Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, Rehovot, Israel; MIGAL Galilee Research Institute LTD, Kiryat Shemona, Israel; Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, CA, United States
Danay, O., MIGAL Galilee Research Institute LTD, Kiryat Shemona, Israel;
Bilbao, C., Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, CA, United States;
McHugh, T., Western Regional Research Center, United States Department of Agriculture, Agricultural Research Service, Albany, CA, United States
Fungal chitosan was produced from brown Agaricus bisporus, white Agaricus bisporus, and Pleurotus ostreatus mushrooms (commercially known as brown portobello, white protobello, and oyster mushrooms, respectively) by utilizing a classic alkali deacetylation protocol (PI), as well as a new protocol (PII) that involves a freeze-thawing cycle. The new protocol (PII) has led up to a twofold increase in the obtained chitosan's yield, a more efficient deacetylation process that resulted in up to a threefold decrease in its acetylated units, and a whiter color. For instance, using the PII protocol, 1 g of dry Pleurotus ostreatus mushrooms yielded 44.3 mg of chitosan that contained only 14.8% acetylated units, and had a whiteness index of 80.3. For comparison, using the classic PI protocol, 1 g of dry Pleurotus ostreatus mushrooms yielded only 22.4 mg of chitosan with 44.1% acetylated units, and a whiteness index of 75.7. Gel permeation chromatography, FTIR, NMR, UV, elemental analysis, X-ray diffractometry, and thermogravimetric analysis were all used to characterize the prepared fungal chitosan samples and examine their physical properties (viscosity, color, hydrophobicity, and solubility). Microbiological studies have revealed the yielded chitosan samples have demonstrated biological activity against Gram-positive Bacillus subtilis, Gram-negative Escherichia coli bacteria, and Saccharomyces cerevisiae yeast. The prepared fungal-sourced chitosan samples were also compared with the crustacean-sourced commercial chitosan all throughout this paper studies. It can be concluded that the PII protocol allows for the formation of fungal chitosan with quality and properties that do not fall short of those found in the crustacean-sourced chitosan. This study therefore presents an efficient method for the production of non-animal sourced chitosan, which is extremely desired in the food industry because it overcomes the limitations of animal-sourced chitosan and allows to expand this material use. In addition, the presented freeze-thaw cycle technique can also be used to yield and modify other edible hydrocolloids. © 2018 Elsevier Ltd
