Displaying publications 1 - 20 of 85 in total

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  1. Ramadhan K, Huda N, Ahmad R
    Poult Sci, 2012 Jul;91(7):1703-8.
    PMID: 22700518 DOI: 10.3382/ps.2011-01926
    In this study, the effect of the addition of different cryoprotectants on the freeze-thaw stability of duck surimi-like material (DSLM) was tested. A 6% (wt/wt) low-sweetness cryoprotectant (i.e., polydextrose, trehalose, lactitol, or palatinit) was added to a 3-kg portion of DSLM, and the mixture was subjected to freeze-thaw cycles during 4 mo of frozen storage. The DSLM with no cryoprotectant added (control) and with a 6% sucrose-sorbitol blend (high-sweetness cryoprotectant) added also were tested. The polydextrose-added sample had the highest water-holding capacity among the sample types tested (P < 0.05), and it retained its higher value during frozen storage. The protein solubility of the cryoprotectant-added samples decreased significantly (P < 0.05) from 58.99 to 59.60% at initial frozen storage (0 mo) to 48.60 to 54.61% at the end of the experiment (4 mo). The gel breaking force of all samples significantly decreased (P < 0.05) at 1 mo; this breaking force then stabilized after further frozen storage for the cryoprotectant-added samples, whereas it continued to decrease in the control samples. Gel deformation fluctuated during frozen storage and was significantly lower (P < 0.05) at the end of experiment than at the beginning. The presence of cryoprotectants reduced the whiteness of DSLM. Samples containing polydextrose, trehalose, lactitol, and palatinit were able to retain the protein solubility, gel breaking force, and deformation of DSLM better than control samples after 4 mo of frozen storage and exposure to freeze-thaw cycles. The effects of these low-sweetness cryoprotectants are comparable to those of sucrose-sorbitol, thus, these sugars could be used as alternatives in protecting surimi-like materials during frozen storage.
    Matched MeSH terms: Freezing*
  2. Al-Bulushi IM, Kasapis S, Dykes GA, Al-Waili H, Guizani N, Al-Oufi H
    J Food Sci Technol, 2013 Dec;50(6):1158-64.
    PMID: 24426029 DOI: 10.1007/s13197-011-0441-x
    The effect of frozen storage on the physiochemical, chemical and microbial characteristics of two types of fish sausages was studied. Fish sausages developed (DFS) with a spice-sugar formulation and commercial fish sausages (CFS) were stored at -20 °C for 3 months. Fresh DFS contained 12.22% lipids and had a 3.53 cfu/g total bacteria count (TBC) whereas, CFS contained 5.5% lipids and had a 4.81 cfu/g TBC. During storage, TBC decreased significantly (p  0.05) in CFS. A peroxide value (PV) was not detectable until week four and eight of storage in CFS and DFS, respectively. The salt-soluble proteins (SSP) level was stable in DFS but in CFS it declined significantly (p  0.05) in both sausage types. This study showed that the effect of storage at -20 °C on fish sausages characteristics varied between formulations and depended on the ingredients of fish sausages.
    Matched MeSH terms: Freezing
  3. Muthanna AM, Al-Qubati YA
    Malays Fam Physician, 2020;15(3):83-85.
    PMID: 33329867
    A keloid represents an excessive overgrowth of skin beyond the boundaries of an injury. Earlobe keloids usually follow ear piercing and can become large, sometimes producing remarkable disfigurement. Surgical excision, pressure dressing, intralesional corticosteroid injection, cryosurgery, radiation, and lasers have all been used to treat earlobe keloids. However, none has produced uniformly satisfactory results. Combinations of more than one modality have also been employed to yield successful outcomes. We describe cryotherapy as a single modality to treat seven-year-old, multiple earlobe keloids. Three cryotherapy sessions with two freezing-thawing cycles of 30-40 seconds' freezing time and two minutes' thawing time, undertaken one month apart, resulted in complete flatness of the keloids and no recurrence after 5 years. We also evaluate keloid-related and operational factors that determine the success of cryotherapy as a monotherapy for earlobe keloids.
    Matched MeSH terms: Freezing
  4. Oslan SNH, Halim M, Ramle NA, Saad MZ, Tan JS, Kapri MR, et al.
    Cryobiology, 2017 12;79:1-8.
    PMID: 29037980 DOI: 10.1016/j.cryobiol.2017.10.004
    The efficacy of attenuated strain of gdhA derivative Pasteurella multocida B:2 mutant as a live vaccine to control haemorrhagic septicaemia (HS) disease in cattle and buffaloes has been demonstrated. In order to use P. multocida B:2 mutant as a commercial product, it is essential to optimise its formulation for high viability and stability of the live cells. The effectiveness of freeze-drying process using different protective agent formulations for improving cells viability was explored. Sugar and nitrogen compounds were used as protective agents in freeze-drying and the capability of these compounds in maintaining the viability of mutant P. multocida B:2 during subsequent storage was investigated. A complete loss in viability of freeze-dried mutant P. multocida B:2 was monthly observed until 6-12 months of storage at -30 °C, 4 °C and 27 °C when nitrogen compound or no protective agent was added. Trehalose and sucrose showed significantly high survival rate of 93-95% immediately after freeze-drying and the viability was retained during the subsequent storage at -30 °C and 4 °C. A smooth cell surface without any cell-wall damage was observed for the cells formulated with trehalose under scanning electron micrograph. This study presented a freeze-drying process generating a dried live attenuated vaccine formulation with high stability for commercial applications.
    Matched MeSH terms: Freezing/adverse effects
  5. Rosdi MRH, Ahmad Razali MA, Ku Ishak KM, Ariffin A
    ACS Omega, 2020 Jun 23;5(24):14473-14480.
    PMID: 32596585 DOI: 10.1021/acsomega.0c01114
    Pour point depressant (PPD) emulsion has been gaining attention in crude oil transportation owing to its potential to solve solidification issues that arise in cold climate environments. An emulsion system provides a wide range of temperature application that combines good shelf life and tunable thermal properties to tackle this problem. These features can be achieved by incorporating an antifreeze agent into the emulsion. One of the most commonly used antifreeze agents is ethylene glycol (EG). Hence, this study focuses on the thermal properties and droplet size growth of PPD emulsions that were aged in variable concentrations of EG solution. EG50 exhibited the lowest freezing temperature of -44 °C, while EG25 demonstrated the lowest vitrification temperature of -68.7 °C. The particle size of the emulsions underwent a significant reduction from 332.3 to 228.9 nm upon the stepwise EG concentration increment to EG50. However, when the concentration was increased to EG75, a slight increase in the emulsion particle size was observed with a recorded value of 237.8 nm. Thus, it is concluded that EG50 represents the optimum concentration for delivering the best freezing protection and producing a smaller droplet particle size.
    Matched MeSH terms: Freezing
  6. Tan, B.H., Azhar, M.E.
    MyJurnal
    Channa striatus (“haruan”) fish destined for fillet preparation was subjected to two freezing treatments, freezing with distilled water (FW) or freezing directly without distilled water (DF). Fish that was freshly processed without freezing served as control (C). Fillet yield (%) was in the range 33.8% to 35.3% and the highest yield was recorded in FW samples. Whole Fillet Powder (WFP) was prepared from the fillets through low temperature vacuum oven drying (50°C) and its composition and physicochemical properties were assessed. There was no significant difference in moisture and protein contents of all samples (p > 0.05). All WFP were generally dark in colour with whiteness indices ranging from 55.23 - 63.98. The redness (a*) values were 4.33, 11.12, 8.83 whilst the yellowness (b*) were 19.31, 23.04, 21.20 for C, WFP-FW and WFP-DF respectively. WFPs were generally high in histidine, arginine, threonine and tyrosine when compared to egg whites and these (except histidine) and other amino acids (serine, glycine, methionine and phenylalanine) were significantly higher (p < 0.05) in WFP-FW compared to other samples. Overall, freezing treatments affected the composition and physicochemical properties of WFPs.
    Matched MeSH terms: Freezing
  7. Halim N, Kuntom A, Shinde R, Banerjee K
    J AOAC Int, 2020 Sep 01;103(5):1237-1242.
    PMID: 33241391 DOI: 10.1093/jaoacint/qsaa041
    BACKGROUND: Indaziflam (IND) is a herbicide that is used in palm oil plantations for broad spectrum management of weeds. Until now, no validated method has been available for residue estimation of this herbicide in palm oil products.

    OBJECTIVE: In this study, we report a rapid method for the residue analysis of IND and its metabolites, viz., IND-carboxylic acid, diaminotriazine, and triazine indanone in a wide range of palm oil matrices using liquid chromatography-tandem mass spectrometry (LC-MS/MS).

    METHOD: The optimized sample preparation workflows included two options: (1) acetonitrile extraction (QuEChERS workflow), followed by freezing at -80°C and (2) acetonitrile extraction, followed by cleanup through a C18 solid phase extraction (SPE) cartridge. The optimized LC runtime was 7 min. All these analytes were estimated by LC-MS/MS multiple reaction monitoring.

    RESULTS: Both sample preparation methods provided similar method performance and acceptable results. The limit of quantification (LOQ) of IND, IND-carboxylic acid, and triazine indanone was 0.001 mg/kg. For diaminotriazine, the LOQ was 0.005 mg/kg. The method accuracy and precision complied with the SANTE/12682/2019 guidelines of analytical quality control.

    CONCLUSIONS: The potentiality of the method lies in a high throughput analysis of IND and its metabolites in a single chromatographic run with high selectivity and sensitivity. Considering its fit-for-purpose performance, the method can be implemented in regulatory testing of IND residues in a wide range of palm oil matrices that are consumed and traded worldwide.

    HIGHLIGHTS: This work has provided a validated method for simultaneous residue analysis of indaziflam and its metabolites in crude palm oil and its derived matrices with high sensitivity, selectivity, and throughput.

    Matched MeSH terms: Freezing
  8. Khumran AM, Yimer N, Rosnina Y, Wahid H, Ariff MO, Homayoun H, et al.
    Vet World, 2019 Apr;13(4):649-654.
    PMID: 32546907 DOI: 10.14202/vetworld.2020.649-654
    Aim: The aim of this study was to investigate the effects of different concentration of butylated hydroxytoluene (BHT) on sperm membrane surface protein "P25b" from cryopreserved bull semen in either lecithin based Bioxcell® (BX) or two egg-yolk based extenders, tris-egg yolk (TEY), and citrate-egg yolk (CEY).

    Materials and Methods: Forty-five semen samples, 15 each were extended with either BX, TEY, or CEY extender which contained different concentrations (0.0 - control, 0.5, 1.0, 1.5, 2.0, and 3.0 mM/mL) of BHT. The extended semen samples were frozen at a concentration of 20×106/mL in 0.25 mL straws and stored in liquid nitrogen for 2weeks. The frozen samples were thereafter thawed, proteins extracted and analyzed for quantities of protein P25b through direct sodium dodecyl sulfate-polyacrylamide gel electrophoresis gel densitometry. Peptides were confirmed by Western blotting (WB).

    Results: Results showed that supplementation of BHT improved (p<0.05) quantity of protein P25b at concentrations of 0.5mM/mL for BX and at 1.0 mM/mL for TEY and CE when compared with the controls and other treatments.

    Conclusion: BHT supplementation at 0.5 in BX and 1.0 mM/mL in TEY and CEY has protected bull sperm fertility marker protein P25b in frozen-thawed bull sperm.

    Matched MeSH terms: Freezing
  9. Ma NL, Teh KY, Lam SS, Kaben AM, Cha TS
    Bioresour Technol, 2015 Aug;190:536-42.
    PMID: 25812996 DOI: 10.1016/j.biortech.2015.03.036
    This study demonstrates the use of NMR techniques coupled with chemometric analysis as a high throughput data mining method to identify and examine the efficiency of different disruption techniques tested on microalgae (Chlorella variabilis, Scenedesmus regularis and Ankistrodesmus gracilis). The yield and chemical diversity from the disruptions together with the effects of pre-oven and pre-freeze drying prior to disruption techniques were discussed. HCl extraction showed the highest recovery of oil compounds from the disrupted microalgae (up to 90%). In contrast, NMR analysis showed the highest intensity of bioactive metabolites obtained for homogenized extracts pre-treated with freeze-drying, indicating that homogenizing is a more favorable approach to recover bioactive substances from the disrupted microalgae. The results show the potential of NMR as a useful metabolic fingerprinting tool for assessing compound diversity in complex microalgae extracts.
    Matched MeSH terms: Freezing
  10. Sim, S.Y., Noor Aziah, A.A., Teng, T.T., Cheng, L.H.
    MyJurnal
    The effects of food gums addition on wheat dough freeze-thaw and frozen storage stability were studied. Thermal and dynamic mechanical properties of frozen wheat dough without yeast addition were
    determined by means of Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA).
    DSC results revealed that food gums showed the ability to increase freeze-thaw stability in frozen-stored
    samples wherein lower difference in melting enthalpy between first and second freeze-thaw cycle was shown. Based on DMA results, in general, difference between Tg’ and storage temperature (- 18°C) of dough became smaller upon addition of food gums. This may have a practical implication whereby the unfrozen phase could be better protected against physical degradation.
    Matched MeSH terms: Freezing
  11. Normah, I., Cheow, C.S., Chong, C.L.
    MyJurnal
    Diacylglycerol at 1 or 6% was added into refined bleached and deodorized palm oil (RBDPO) and crystallized from the melt in a thermally controlled water bath at 22°C for 90 min. Slurries were withdrawn after 5, 15, 30, 60 and 90 min of crystallization for solid fat content (SFC) and crystal morphology studies. Crystallization was also performed in a similar manner using a Labmax reactor connected to a FBRM detector to obtain the information on crystal count and size distribution during crystallization. SFC of the slurries increased with increase in crystallization time up to a certain level followed by a plateau. SFC of RBDPO added with DAG was also higher with the increase in percentage of DAG added and no induction time was observed to initiate crystallization in RBDPO added with DAG. The addition of DAG caused rapid crystallization of RBDPO as observed by enhance nucleation and larger crystal size with increase in the percentages of DAG added.
    Matched MeSH terms: Freezing
  12. Pon, S.Y., Lee, W.J., Chong, G.H.
    MyJurnal
    Ice cream contains high sugar content and therefore it is in contradiction with the concept of healthy diet. The objective of this study is to determine the suitability of using stevia as an alternative natural sweetener in making ice cream. In- house ice cream formulation (as the control) and three different concentrations of stevia ice cream formulations of (A, B and C) were used. Physical properties of the ice cream such as the overrun, total soluble solid, meltdown rate, rheology, and textural properties were evaluated. All ice cream samples exhibited a nonNewtonian flow with pseudoplastic behavior. Stevia ice cream has a lower melting rate and has a higher sustainability. The power law also showed that apparent viscosities of stevia ice cream were higher. Therefore, stevia can be used as a natural sugar substitute in ice cream production.
    Matched MeSH terms: Freezing
  13. Lee JS, Lo YL, Chye FY
    This study was carried out to elucidate the effect of three types of cation (K+, Ca2+ and Na+) at various concentrations on the gelling properties of untreated Eucheuma cottoni, with the ultimate aim to explore the possibility of utilizing the seaweed in its natural form as gelling agent. Results obtained suggest that E. cottonii also exhibited the dramatic cation specificity of k-carrageenan, in which the dependence of gel strength follows the order: K+ > Ca2+ > Na+. As expected, cations addition exerts adverse effect on the syneresis, water holding capacity and freeze-thaw stability of the seaweed gel. Water holding capcity of the gel is however independent of the increased concentrations of K+(p>0.05). Storage duration and storage temperature significantly (p<0.05) affect the syneresis and water holding capacity of the gel. Among the cations, K+ appears to be better in improving the gel properties of the seaweed.
    Matched MeSH terms: Freezing
  14. Qasim SSB, Nogueria LP, Fawzy AS, Daood U
    AAPS PharmSciTech, 2020 Jun 16;21(5):173.
    PMID: 32548717 DOI: 10.1208/s12249-020-01708-x
    Innovative strategies for periodontal regeneration have been the focus of research clusters across the globe for decades. In order to overcome the drawbacks of currently available options, investigators have suggested a novel concept of functionally graded membrane (FGM) templates with different structural and morphological gradients. Chitosan (CH) has been used in the past for similar purpose. However, the composite formulation of composite and tetracycline when cross-linked with glutaraldehyde have received little attention. Therefore, the purpose of the study was to investigate the drug loading and release characteristics of novel freeze gelated chitosan templates at different percentages of glutaraldehyde. These were cross-linked with 0.1 and 1% glutaraldehyde and loaded with doxycycline hyclate. The electron micrographs depicted porous morphology of neat templates. After cross-linking, these templates showed compressed ultrastructures. Computerized tomography analysis showed that the templates had 88 to 92% porosity with average pore diameter decreased from 78 to 44.9 μm with increasing concentration. Fourier transform infrared spectroscopy showed alterations in the glycosidic segment of chitosan fingerprint region which after drug loading showed a dominant doxycycline spectral composite profile. Interestingly, swelling profile was not affected by cross-linking either at 0.1 and 1% glutaraldehyde and template showed a swelling ratio of 80%, which gained equilibrium after 15 min. The drug release pattern also showed a 40 μg/mL of release after 24 h. These doxycycline-loaded templates show their tendency to be used in a functionally graded membrane facing the defect site.
    Matched MeSH terms: Freezing*
  15. Nopianti R, Huda N, Ismail N, Ariffin F, Easa AM
    J Food Sci Technol, 2013 Aug;50(4):739-46.
    PMID: 24425976 DOI: 10.1007/s13197-011-0394-0
    Physicochemical properties of threadfin bream surimi with different levels of polydextrose (3%, 6%, 9% and 12%), raw surimi, raw surimi with addition sodium tripolyphosphate and commercial surimi (sucrose) during 6 months of frozen storage were investigated. The analyses included the measurement of Ca(2+)-ATPase, sulfhydryl contents, protein solubility, sodium dodecyl sulfate polyacrylamide gel electrophoresis, differential scanning calorimetry and scanning electron microscopy. The Ca(2+)-ATPase, sulfhydryl content and protein solubility levels added with 3%, 6%, 9% and 12% polydextrose can be maintained until the 6 months of storage by 47.33%, 41.60% and 51.41%, respectively. Differential scanning calorimetry showed decreases in thermal stabilization of myosin with regard to transition termperature. Analysis by scanning electron microscopy demonstrated that the number of pores formed was increased after storage. This study suggested that surimi stored with the polydextrose as a cryoprotectant was able to maintain physicochemical of surimi better compared to raw surimi with no additives or raw surimi with sodium tripolyphosphate.
    Matched MeSH terms: Freezing
  16. Nopianti, R., Huda, N., Fazilah, A., Ismail, N., Easa, A. M.
    MyJurnal
    The effects of different types of low-sweetness sugar (lactitol, maltodexrin, palatinit, polydextrose,
    trehalose) on the physicochemical properties of threadfin bream (Nemipterus spp.) surimi during six months of frozen storage were investigated. The characteristics analyzed were moisture content, pH, water-holding capacity, whiteness, folding test, gel strength, expressible moisture, and texture profile analyses. Generally, the cryoprotective effectiveness decreased as the storage time increased. Polydextrose was able to maintain a water-holding capacity of 77.0%, 98.6% whiteness, a folding test value of 100%, and a gel strength of 53.6% compared with its initial value during six months of frozen storage. Meanwhile, sucrose was able to maintain a water-holding capacity of 80.3%, 98.6% whiteness, a folding test value of 75%, and a gel strength of 56.8%
    compared with its initial value. Raw surimi was able to maintain water holding capacity of 62.2%, 98.7% whiteness, a folding test value of 75%, and a gel strength of 36.0% compared with its initial value. It is suggested that, polydextrose as a potential alternative cryoprotectant to replace other low-sweetness sugars.
    Matched MeSH terms: Freezing
  17. Kaka A, Wahid H, Rosnina Y, Yimer N, Khumran AM, Sarsaifi K, et al.
    Anim. Reprod. Sci., 2015 Feb;153:1-7.
    PMID: 25544152 DOI: 10.1016/j.anireprosci.2014.12.001
    The present study was conducted to determine the effects of supplementing α-linolenic acid (ALA) into BioXcell(®) extender on post-cooling, post-thawed bovine spermatozoa and post thawed fatty acid composition. Twenty-four semen samples were collected from three bulls using an electro-ejaculator. Fresh semen samples were evaluated for general motility using computer assisted semen analyzer (CASA) whereas morphology and viability with eosin-nigrosin stain. Semen samples extended into BioXcell(®) were divided into five groups to which 0, 3, 5, 10 and 15 ng/ml of ALA were added, respectively. The treated samples were incubated at 37°C for 15 min for ALA uptake by sperm cells before being cooled for 2 h at 5°C. After evaluation, the cooled samples were packed into 0.25 ml straws and frozen in liquid nitrogen for 24 h before thawing and evaluation for semen quality. Evaluation of cooled and frozen-thawed semen showed that the percentages of all the sperm parameters improved with 5 ng/ml ALA supplement. ALA was higher in all treated groups than control groups than control group. In conclusion, 5 ng/ml ALA supplemented into BioXcell(®) extender improved the cooled and frozen-thawed quality of bull spermatozoa.
    Matched MeSH terms: Freezing
  18. Tarig AA, Wahid H, Rosnina Y, Yimer N, Goh YM, Baiee FH, et al.
    Vet World, 2017 Jun;10(6):672-678.
    PMID: 28717321 DOI: 10.14202/vetworld.2017.672-678
    AIM: The objective of this study was to evaluate the effects of different concentrations of soybean lecithin (SL) and virgin coconut oil (VCO) in Tris-based extender on chilled and frozen-thawed bull semen quality parameters.

    MATERIALS AND METHODS: A total of 24 ejaculates were collected from four bulls via an electroejaculator. Semen samples were diluted with 2% VCO in Tris-based extender which consists of various concentrations of SL (1, 1.25, 1.5, and 1.75%). A 20% egg yolk in Tris used as a positive control (C+). The diluted semen samples were divided into two fractions; one for chilling which were stored at 4°C for 24, 72, and 144 h before evaluated for semen quality parameters. The second fraction used for freezing was chilled for 3 h at 4°C, packed into 0.25 mL straws and then cryopreserved in liquid nitrogen. The samples were then evaluated after 7 and 14 days. Chilled and frozen semen samples were thawed at 37°C and assessed for general motility using computer-assisted semen analysis, viability, acrosome integrity and morphology (eosin-nigrosin stain), membrane integrity, and lipid peroxidation using thiobarbituric acid reaction test.

    RESULTS: The results showed that all the quality parameters assessed were significantly (p<0.05) improved at 1.5% SL concentration in chilled semen. Treatment groups of 1, 1.25, 1.5, and 1.75% SL were higher in quality parameters than the control group (C+) in chilled semen. However, all the quality parameters in frozen-thawed semen were significantly higher in the C+ than the treated groups.

    CONCLUSION: In conclusion, supplementation of 1.5% SL in 2% VCO Tris-based extender enhanced the chilled bull semen. However, there was no marked improvement in the frozen-thawed quality parameters after treatment.

    Matched MeSH terms: Freezing
  19. Ruzilawati AB, Wahab MS, Imran A, Ismail Z, Gan SH
    J Pharm Biomed Anal, 2007 Apr 11;43(5):1831-5.
    PMID: 17240100
    In this study, the development and validation of a high-performance liquid chromatography (HPLC) assay for determination of repaglinide concentration in human plasma for pharmacokinetic studies is described. Plasma samples containing repaglinide and an internal standard, indomethacin were extracted with ethylacetate at pH 7.4. The recovery of repaglinide was 92%+/-55.31. Chromatographic separations were performed on Purospher STAR C-18 analytical column (4.8 mm x 150 mm; 5 microm particle size). The mobile phase composed of acetonitrile-ammonium formate (pH 2.7; 0.01 M) (60:40, v/v). The flow rate was 1 ml/min. The retention time for repaglinide and indomethacin were approximately 6.2 and 5.3 min, respectively. Calibration curves of repaglinide were linear in the concentration range of 20-200 ng/ml in plasma. The limits of detection and quantification were 10 ng/ml and 20 ng/ml, respectively. The inter-day precision was from 5.21 to 11.84% and the intra-day precision ranged from 3.90 to 6.67%. The inter-day accuracy ranged 89.95 to 105.75% and intra-day accuracy ranged from 92.37 to 104.66%. This method was applied to determine repaglinide concentration in human plasma samples for a pharmacokinetic study.
    Matched MeSH terms: Freezing
  20. Kwan TK, Poh CH, Perumal R, Gower DB
    Biochem. Mol. Biol. Int., 1994 Oct;34(4):661-70.
    PMID: 7866291
    The metabolism of varying quantities of pregnenolone has been studied in nuclei-free homogenates from Macaca fascicularis testes by using capillary gas chromatography, after derivatization of metabolites as O-methyl oximes/trimethylsilyl ethers. Evidence was obtained indicating that both pathways for testosterone biosynthesis were operating. 5-Androstene-3 beta, 17 beta-diol was formed in especially high quantities. Two 16-androstenes, namely 5,16-androstadien-3 beta-ol and 5 alpha-androst-16-en-3 beta-ol, were also quantitatively important as metabolites. Co-incubation of stored homogenates with relaxin resulted in 80-100% reduction of the formation of all metabolites quantified except for 5 alpha-androst-16-en-3-one, which was stimulated. Freezing the homogenates at -10 degrees C for 3 weeks resulted in marked 4- to 6-fold reduction in the yields of testosterone and of the 5-ene and 4-ene metabolites from pregnenolone.
    Matched MeSH terms: Freezing*
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