000 06145nas|a2200493 a 4500
005 20260817162831.0
008 050805s2004 th uu|m rtt 0| a1eng d
035 _a.b11967390
099 9 _aAIT Diss. no.AE-04-06
100 0 _aYudi Pranoto
245 1 0 _aApplication of alginate and chitosan edible films incorporating natural antimicrobial agents
260 _aPathum Thani, Thailand :
_bAsian Institute of Technology,
_c2004
300 _a183 p. :
_bill.
490 1 _aDissertation ;
_vno. AE-04-06
502 _aThesis (Ph.D.) - Asian Institute of Technology, 2004
500 _aA dissertation submitted in partial ful{uFB01}llment ofthe requirements for the degree of Doctor of Engineering, School of Environment, Resources and Development
520 _aFood quality and safety demands are becoming more and more intensive and speci{uFB01}c with more information available to the buyers. Consumer awareness for safe, high quality, long shelf life, fresher, minimally processed and ready to eat foods has increased in recent times. The use of edible {uFB01}lms or coatings is one of the most effective methods in maintaining the quality and extending shelf life of processed foods. They can also function as a carrier of ingredients, such as antioxidants and antimicrobial agents. Alginate and chitosan are polysaccharides, abundantly available as natural materials. Coating meat products with alginate and chitosan has been shown to protect moisture loss, retard microbial growth and reduce lipid oxidation. In addition, it is known that some spice oils have antimicrobial and antioxidative activity. There is a limited research about employing these natural agents from plants to produce active edible {uFB01}lms or coatings for foods preservation. This study was carried out to utilize the beneficial potency of natural substances (Spice oils) by incorporating into alginate and chitosan {uFB01}lms to obtain active edible {uFB01}lms and coatings. Initially, garlic, citronella and onion oils were tested for antimicrobial and antioxidative activities to select the most potent one. Antimicrobial {uFB01}lms were then studied by incorporating antimicrobial agents such as garlic oi] (selected oil), potassium sorbate and nisin. The latter two are well known chemical and (bacteriocin) antimicrobial agents respectively. Five food pathogenic bacteria such as Escherichia coli, Salmonella wphimurium, Staphylococcus azrreus, Lister-11 monocytogenes and Bacillus cererrs were used to test antimicrobial activity of edible {uFB01}lms. Meatball was used as a model product to examine the ef{uFB01}cacy of active edible coatings for quality preservation. When tested against the above mentioned bacteria, it was found that garlic oil had better antimicrobial activity than citronella and onion oils. Its antioxidant activity measured using 1,1-diphenyl-2{u2014}picrylhydrazyl (DPPI{u2014}I) and deoxyribonucleic acid (DNA) cleavage protection methods was also found to be better than the other oils. The addition of glycerol at 40% (w/w of {uFB01}lm materials) as a plasticizer modi{uFB01}ed the mechanical, physical and microstructural properties of alginate and chitosan {uFB01}lms. In the alginate {uFB01}lms, glycerol reduced tensile strength from 73.36 to 66.11 MPa, while in chitosan {uFB01}lms it reduced tensile strength from 49.63 to 6.53 MPa. The elongation at break for alginate {uFB01}lm increased slightly from 2.65 to 4.05% by addition of glycerol. The elongation at break for chitosan {uFB01}lms was from 6.21 to 30.96%. In addition, glycerol caused an increase in water vapor permeability (WVP) value from 16.13 to 20.32 g.mm/m2.day.kPa in alginate {uFB01}lms and from 23.09 to 26.72 g.mmx{u2019}m3.day.kPa in chitosan {uFB01}lms. Glycerol addition reduced the microstructure cavities in alginate {uFB01}lms, while in chitosan {uFB01}lm it modi{uFB01}ed its compact structure in multilayers as observed by 3 Scanning Electron Microscopy (S EM). As chitosan and alginate have complementary prOperties in terms of charge, composite and bilayer {uFB01}lms were made. Composite {uFB01}lms made of varying ratios between alginate and chitosan did not result in {uFB01}lms with desirable characteristics. In bilayer {uFB01}lms, it was found that laminating chitosan onto alginate {uFB01}lm could not replace the role of Ca ion as crosslinking agent in term of mechanical prOperties. Bilayer {uFB01}lms made from alginate
650 0 _aMeatballs
_xPreservation
650 0 _aChitosan
650 0 _aAlginates
650 0 _aAnti-infective agents
700 1 _aRakshit, Sudip Kumar,
_eChairperson
700 1 _aSalokhe, Vilas M.,
_eExamination Committee
700 1 _aNguyen T. Kim Oanh,
_eExamination committee
700 0 _aPhaisan Wuttijumnong,
_eExamination committee
700 1 _aPark, Hyun J.,
_eExamination committee
710 2 _aQuality for Undergraduate Education Project Government of lndonesia,
_eScholarship donor
810 2 _aAsian Institute of Technology.
_tDissertation ;
_vno. AE-04-06
856 _3Full-Text
_uhttp://203.159.5.9/ait-thesis/detail.php?q=B00160
907 _a.b11967390
_bmnait
_cu
902 _a240329
998 _b0
_c050729
_dm
_ea
_fu
_g0
945 _lmnait
945 _lmnait
945 _lmnait
945 _lmnarc
942 _c20
942 _c40
909 _aBarcode : 30050004614185
_bCREATED : 2005-07-29
_cRECORD # : i12453869
_dLPATRON : 1023858
_eLCHKIN : 2016-01-09
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 8
_jTOT RENEW : 4
909 _aBarcode : 30050120564389
_bCREATED : 2005-07-29
_cRECORD # : i12453882
_dLPATRON : 1025400
_eLCHKIN : 2015-12-12
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 6
_jTOT RENEW : 7
909 _aBarcode : 30050120564397
_bCREATED : 2013-11-29
_cRECORD # : i12749370
_dLPATRON : 1015151
_eLCHKIN : 2019-02-04
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 3
_jTOT RENEW : 4
909 _aBarcode : 30050160038955
_bCREATED : 2016-01-19
_cRECORD # : i12869934
_dLPATRON : 0
_eLCHKIN : -
_f# RENEWALS : 0
_g# OVERDUE : 0
_hIUSE3 : 0
_iTOT CHKOUT : 0
_jTOT RENEW : 0
999 _c6462
_d6462