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Effect of chemical and physical parameters on 2-acetyl-1-pyrroline production by Acremonium nigricans and its preservation by encapsulation (Record no. 34189)

MARC details
000 -LEADER
fixed length control field	06843nas\|a2200421 i 4500
005 - DATE AND TIME OF LATEST TRANSACTION
control field	20260818094859.0
008 - FIXED-LENGTH DATA ELEMENTS--GENERAL INFORMATION
fixed length control field	021226s2000 th uzm rtt 00\| a1eng d
035 ## - SYSTEM CONTROL NUMBER
System control number	.b11871982
099 #9 - LOCAL FREE-TEXT CALL NUMBER (OCLC)
Classification number	AIT Diss. no.PH-00-2
100 0# - MAIN ENTRY--PERSONAL NAME
Personal name	Muanmai Apintanapong
245 10 - TITLE STATEMENT
Title	Effect of chemical and physical parameters on 2-acetyl-1-pyrroline production by Acremonium nigricans and its preservation by encapsulation
260 ## - PUBLICATION, DISTRIBUTION, ETC.
Place of publication, distribution, etc.	Bangkok :
Name of publisher, distributor, etc.	Asian Institute of Technology,
Date of publication, distribution, etc.	2000
300 ## - PHYSICAL DESCRIPTION
Extent	157 leaves
490 1# - SERIES STATEMENT
Series statement	Dissertation ;
Volume/sequential designation	no. PH-00-2
500 ## - GENERAL NOTE
General note	A dissertation submitted in pa1tial fulfillment of the requirements for the degree of Doctor of Technical Science.
502 ## - DISSERTATION NOTE
Dissertation note	Thesis (Ph.D.) - Asian Institute of Technology, 2000
520 ## - SUMMARY, ETC.
Summary, etc.	The production of 2-acetyl-1-pyrroline (ACPY), the main compound contributing to the fragrance of aromatic rice, by the fungi Acremonium nigricans, was investigated. The effect of chemical parameters (media composition and inorganic nitrogen source) on ACPY production was studied in shake flask fermentation. The physical parameters (such as aeration rate, agitation speed and pH control) and its kinetic study were determined in a 5 1 bioreactor. Encapsulation of ACPY with gum acacia and maltodextrin using the spray and freeze drying methods to retain aroma during storage was also conducted. Odor evaluation was done in the application of ACPY in milled rice. The volatile compounds of the culture broth of A. mgrzcans were extracted and analyzed by GLC and GLC-MS. A peak eluted at 5.43 min by GLC-MS gave the mass spectrum which was identical to that of ACPY from pandan leaf extracts and authentic compounds from chemical synthesis. From the Plackett-Burman statistical design, glucose gave a positive effect on ACPY production whereas potassium phosphate, biotin and Capantothenate were identified to have an inhibitory effect at the 60 % confidence level. The highest ACPY production was obtained from an optimized synthetic medium consisting of 20 mg/I biotin, 100 mg/l Ca-pantothenate, 300 mg/I pyridoxine.HCl, 400 mg/I thiamine, and 1000 mg/l inositol. The optimum concentrations of glucose, mono-potassium phosphate/dipotassium phosphate, and sodium chloride were 15, 1.27/0.1 and 0.25 g/l, respectively. The amount of ACPY obtained from this medium at 120 hours of cultivation was 3.45 mg/l. The culture media with ammonium nitrate and urea, as the inorganic nitrogen source, were observed to have high glucose consumption compared with media containing ammonium chloride. These inorganic nitrogen sources were not suitable precursors for ACPY production. In the 5 I bioreactor, the highest amount (3.06 mg/l) of ACPY was obtained at 0.875 vvm and 400 rpm with no pH control. From statistical analysis, aeration rate and agitation speed affected ACPY production. The effect of pH control at 0.875 vvm aeration rate and 300 rpm agitation speed was studied and the result showed that pH affected ACPY production. Cultivation of microorganisms at constant pH 4.5 yielded low concentrations of ACPY. Kinetic studies showed that specific growth rate, specific consumption rate, and product formation rate tended to increase with aeration rate and agitation speed. With constant pH of 4.5, maximum cell dry weight, specific growth rate, biomass yield coefficient, product yield coefficient, and product formation rate decreased. Substrate consumption rate at constant pH of 4.5 was higher than without pH control. For odor evaluation, the panelists used the term "pandan-like aroma" to describe ACPY from both pandan leaves and culture broth. More than 70 % of the panelists liked the odor from both samples. An odor threshold of 0.156 ppb of ACPY (from culture broth) in water was obtained from untrained panelists. Qualitative assessment of ACPY application in milled rice was then carried out. The samples with added ACPY from partially purified culture broth obtained a higher score for aromatic rice flavor than the control. However, overall acceptability was low. In ACPY encapsulation, spray-dried powders of 70:30 gum acacia-maltodextrin gave a minimum reduction of ACPY (27.7 %) after 72 days of storage. Freeze-dried powders from 70:30, 60:40, and 0:100 gum acacia-maltodextrin mixtures had no loss of ACPY within 60 days of storage. Under the scanning electron microscope, it was observed that increased ratios of gum acacia resulted in some deep dents on surfaces. The surfaces in all samples had no cracks or pores. Freeze-dried powders had complex forms and larger particles than spray-dried powders. In the humidification study, exposure of product powders to high relative humidity caused higher moisture contents and change in structure. High ratio maltodextrin powders formed a paste-like mass, whereas their moisture contents were lower. At high relative humidity, capsules were completely destroyed while freeze-dried powders were easily contaminated with microorganisms. The best ratio for encapsulation of ACPY was 70:30 gum acacia-maltodextrin mixture through freeze-drying because hygroscopicity was lower and ACPY was not lost. An odor evaluation of rice was conducted by adding encapsulated ACPY (70:30 gum acacia and maltodextrin) from partially purified culture broth to milled rice. The samples with encapsulated ACPY obtained a higher score for aromatic rice flavor than the control. Conversely, the overall acceptability obtained a low score. Some panelists commented that an off odor and lower overall acceptability might have been caused by the encapsulating materials (gum acacia and maltodextrin).
650 #0 - SUBJECT ADDED ENTRY--TOPICAL TERM
Topical term or geographic name entry element	Acremonium
650 #0 - SUBJECT ADDED ENTRY--TOPICAL TERM
Topical term or geographic name entry element	Microencapsulation
General subdivision	Preservation
700 1# - ADDED ENTRY--PERSONAL NAME
Personal name	Jindal, Vinod Kumar,
Relator term	Examination Committee
700 1# - ADDED ENTRY--PERSONAL NAME
Personal name	Visavanathan, C.,
Relator term	Examination committee
700 0# - ADDED ENTRY--PERSONAL NAME
Personal name	Athapol Noomhorm,
Relator term	Chairperson
710 2# - ADDED ENTRY--CORPORATE NAME
Corporate name or jurisdiction name as entry element	Royal Thai Government,
Relator term	Scholarship donor
810 2# - SERIES ADDED ENTRY--CORPORATE NAME
Corporate name or jurisdiction name as entry element	Asian Institute of Technology.
Title of a work	Dissertation ;
Volume/sequential designation	no. PH-00-2
856 ## - ELECTRONIC LOCATION AND ACCESS
Materials specified	Full-Text
Uniform Resource Identifier	<a href="http://203.159.5.9/ait-thesis/detail.php?q=B06487">http://203.159.5.9/ait-thesis/detail.php?q=B06487</a>
907 ## - LOCAL DATA ELEMENT G, LDG (RLIN)
a	.b11871982
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902 ## - LOCAL DATA ELEMENT B, LDB (RLIN)
a	240403
998 ## - LOCAL CONTROL INFORMATION (RLIN)
Operator's initials, OID (RLIN)	0
Cataloger's initials, CIN (RLIN)	021226
First date, FD (RLIN)	m
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945 ## - LOCAL PROCESSING INFORMATION (OCLC)
l	mnait
945 ## - LOCAL PROCESSING INFORMATION (OCLC)
l	mnait
945 ## - LOCAL PROCESSING INFORMATION (OCLC)
l	mnarc
942 ## - ADDED ENTRY ELEMENTS (KOHA)
Koha item type	20-AIT Publication
942 ## - ADDED ENTRY ELEMENTS (KOHA)
Koha item type	40-Archives
909 ## - LOCAL ITEMS USED
Barcode	Barcode : 30050120726582
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Holdings
Not for loan	Home library	Current library	Shelving location	Date acquired	Cost, normal purchase price	Full call number	Barcode	Date last seen	Copy number	Price effective from	Koha item type
Available for Loans	Asian Institute of Technology Library	Asian Institute of Technology Library	AIT Publications	18/08/2026	50.00	AIT Diss. no.PH-00-2	30050120726582	18/08/2026	1	18/08/2026	20-AIT Publication
Available for Loans	Asian Institute of Technology Library	Asian Institute of Technology Library	AIT Publications	18/08/2026	50.00	AIT Diss. no.PH-00-2	30050120726590	18/08/2026	2	18/08/2026	20-AIT Publication
Available for Loans	Asian Institute of Technology Library	Asian Institute of Technology Library	Archives	18/08/2026		AIT Diss. no.PH-00-2	30050160040902	18/08/2026		18/08/2026	40-Archives

Effect of chemical and physical parameters on 2-acetyl-1-pyrroline production by Acremonium nigricans and its preservation by encapsulation (Record no. 34189)

AIT

Asian Institute of Technology Library