Ruggedness Testing of the Official Method for Rot Fragments in Comminuted Tomato Products

1985 ◽  
Vol 68 (5) ◽  
pp. 896-898
Author(s):  
Gerald E Russell
Keyword(s):  
Analysis Of Variance ◽  
Official Method ◽  
Design Technique ◽  
Testing Procedures ◽  
Tube Number ◽  
Sample Amount ◽  
Aoac Method ◽  
Tomato Products ◽  
Ruggedness Testing ◽  
Staining Time

Abstract The official AOAC method for rot fragments in comminuted tomato products (44.224) has been revised on the basis of Youden's ruggedness testing procedures to provide better control over the sources of variability. Two sets of ruggedness tests were carried out to evaluate the type of balance used to weigh the sample, amount of stain, staining time, sieve design, technique used to transfer stained material from beaker to sieve, washing technique used to accumulate stained material at edge of sieve, diameter of eye dropper used to transfer sample from sieve to graduated tube, number of 0.5 mL portions examined, and magnification used to examine prepared slides. A 3-way analysis of variance conducted on amount of stain, transfer technique, and washing technique showed that the transfer and washing techniques were significant areas of variability.

Modification of AOAC Method for Determination of Soluble Solids in Tomato Products

1972 ◽  
Vol 55 (4) ◽  
pp. 809-810
Author(s):  
Frank C Lamb
Keyword(s):  
Sample Preparation ◽  
Excellent Agreement ◽  
Soluble Solids ◽  
Official Method ◽  
Aoac Method ◽  
Centrifugation Technique ◽  
Tomato Products ◽  
Good Agreement

Abstract The official first action method for soluble solids in tomato products, 32.008–32.010, was modified to permit the optional use of an ultracentrifuge to prepare samples for readings in a refractometer. Excellent agreement was obtained between the official method which specifies filtration and the centrifugation technique. Good agreement was also obtained between 2 laboratories using the centrifugation technique. The official method was modified to include the optional use of an ultracentrifuge for sample preparation.

Particle Size and Concentration Adjustments of Tomato Products for Howard Mold Count

1981 ◽  
Vol 64 (3) ◽  
pp. 570-573
Author(s):  
Ruth Bandler ◽  
Stanley M Cichowicz ◽  
◽  
S Cichowicz ◽  
D Floyd ◽  
...  
Keyword(s):  
Particle Size ◽  
Coefficient Of Variation ◽  
Collaborative Study ◽  
Official Method ◽  
Study Results ◽  
Product Standardization ◽  
Aoac Method ◽  
Tomato Products ◽  
Uniform Particle Size ◽  
Mold Count

Abstract The present AOAC method for mold counts of tomato products (44.096) provides no inter-product standardization of concentration among juice, sauce, paste, puree, and catsup; no intra-product standardization of concentration for juice, sauce, and catsup; and no adjustment for degree of comminution. Use of the official method, therefore, could result in an artificially increased mold count for products which have undergone extreme comminution. A new method was developed to adjust all products to the same concentration and grind them to a uniform particle size, thereby ensuring comparable mold counts on products produced by different processes. Collaborative study results showed equal repeatability for both the official and the proposed methods and a lower coefficient of variation for the proposed method.

Allyl Isothiocyanate in Mustard Seed

1970 ◽  
Vol 53 (1) ◽  
pp. 1-3 ◽  
Author(s):  
Donald L Andersen
Keyword(s):  
Allyl Isothiocyanate ◽  
Mustard Seed ◽  
Official Method ◽  
Average Recovery ◽  
Aoac Method ◽  
Aoac Official ◽  
Mustard Seeds ◽  
Column Preparation ◽  
Aoac Official Method

Abstract A new GLC method for the determination of allyl isothiocyanate in mustard seed was compared to a method of the Midwest Research Institute and to a combination of the AOAC official method and the proposed method. Twelve collaborators compared the AOAC method and the GLC method, using whole mustard seeds. Each collaborator assayed three seed portions by both methods. The range, standard deviation, and coefficient of variation are less for each seed portion by the proposed than by the official method. The average recovery value of allyl isothiocyanate in the prepared standard solutions is lower, using the proposed GLC procedure, but seed assay values are significantly and consistently higher for each seed portion when compared with the results for the AOAC method. Reports from the collaborators also indicate that the proposed method is rugged, as the GLC column preparation was subjected to many changes. It is recommended that the GLC method be adopted as official first action.

Collaborative Study of the Quantitative Gas-Liquid Chromatographic Determination of Fusel Oil and Other Components in Whisky

1972 ◽  
Vol 55 (3) ◽  
pp. 549-556
Author(s):  
J H Kahn ◽  
E T Blessinger
Keyword(s):  
Ethyl Acetate ◽  
Collaborative Study ◽  
Chromatographic Determination ◽  
Official Method ◽  
Fusel Oil ◽  
Fusel Alcohols ◽  
Aoac Method ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract Fifteen chemists participated in a collaborative study for the quantitative pas-liquid chromatographic determination of the individual fusel alcohols and ethyl acetate in whisky. Two levels of congeners represented by 4 coded samples of whisky were analyzed by using t h e proposed method, employing a glycerol-1,2,6-hexanetriol column, and the official AOAC method, 9.063-9.065. Since isobutyl and the atnyl alcohols comprise by far the greatest part of fusel oil, their determination is of major importance to the total fusel oil content . Statistical analyses show that the proposed method is superior to the AOAC method for the determination of these alcohols, whereas the official method is superior for the determination of ethyl acetate and n-propyl alcohol. In general, collaborators employing modern instrumentation preferred the proposed method over the AOAC method. The former method also separates and permits the quantitative measurement of active amyl and isoamyl alcohols. The proposed method has been adopted as official first action as an alternative to 9.063–9.065 for the determination of higher alcohols and ethyl acetate in whisky.

scholarly journals Comparative Validation Study to Demonstrate the Equivalence of a Minor Modification to AOAC Method 997.03 [Visual Immunoprecipitate (VIP®) for Listeria] to the Reference Culture Methods

2008 ◽  
Vol 91 (2) ◽  
pp. 365-369 ◽  
Author(s):  
Philip T Feldsine ◽  
David E Kerr ◽  
George S Shen ◽  
Andrew H Lienau
Keyword(s):  
Official Method ◽  
Comparison Study ◽  
Culture Methods ◽  
Environmental Surfaces ◽  
Environmental Surface ◽  
Aoac Method ◽  
Aoac Official ◽  
A Minor ◽  
Comparative Validation ◽  
Aoac Official Method

Abstract The Visual Immunoprecipitate (VIP®) for the Detection of Listeria in Foods and Environmental Surfaces, AOAC Official Method 997.03, has been modified to use a simplified housing for the device. A methods comparison study was conducted to demonstrate the equivalence of this modification to the reference culture methods. Two food matrixes and one environmental surface were analyzed. In total, valid results were obtained from 145 samples and controls. Results showed that the modified VIP for Listeria spp. is equivalent to the reference culture methods for the detection of Listeria.

Collaborative Study of the Determination of Phosphorus in Gelatin, Dessert Preparations, and Mixes

1972 ◽  
Vol 55 (3) ◽  
pp. 581-582
Author(s):  
Roger G Burkepile
Keyword(s):  
Collaborative Study ◽  
Official Method ◽  
Standard Samples ◽  
Preliminary Work ◽  
Aoac Method ◽  
Standard Deviations

Abstract A collaborative study of the proposed method for phosphorus in gelatin, dessert preparations, and mixes has been conducted. The present AOAC method for phosphorus in fertilizers, 2.023–2.025(a), was modified for this study. Preliminary work by the Associate Referee involving 4 phosphorus standard samples compared the proposed method with the official final action AOAC method for gelatin, 23.004. Additionally, phosphorus standard spikes in gelatin at the 1 and 10 mg P2O5, levels were determined by the proposed method. The proposed method is faster and more sensitive than the official method and is as accurate. Five collaborators and the Associate Referee analyzed 4 prepared samples containing various levels of phosphorus by the proposed method. The standard deviations varied from 0.005 for a 225 Bloom gelatin containing an average of 0.273% P2O5 to 0.016 for a strawberry-flavored commercial gelatin with added lecithin containing an average of 0.110% P2O5. The proposed method has been adopted as official first action to replace 23.004, which was repealed, official first action.

Air-Agitation Modification of the AOAC Method for Fly Egg Detection in Tomato Products

1966 ◽  
Vol 49 (5) ◽  
pp. 903-905
Author(s):  
Robert C Riley ◽  
Donald J Prostak
Keyword(s):  
Aoac Method ◽  
Tomato Products

Abstract The present official, first action method for fly eggs and maggots in tomato products, 36.064, was modified by using airagitation in place of hand-rotary shaking. Air-agitation is more efficient than hand swirling both in the number of fly eggs recovered and in the time necessary for analysis.

Determination of Geotrichum Mold in Comminuted Fruits and Vegetables: Collaborative Study

1982 ◽  
Vol 65 (5) ◽  
pp. 1095-1096
Author(s):  
Stanley M Cichowicz ◽  
Ruth Bandler ◽  
◽  
R Bandler ◽  
G Dzidowski ◽  
...  
Keyword(s):  
Crystal Violet ◽  
Fruits And Vegetables ◽  
Collaborative Study ◽  
Green Beans ◽  
Aoac Method ◽  
Tomato Products

Abstract The official AOAC method for determination of Geotrichum mold in canned fruits and vegetables (44.079) requires a series of 3 sieves, Nos. 8, 16, and 230, to separate the packing liquid from the product and the mold from the packing liquid. Although this method has been successful for whole or coarsely chopped products (e.g., green beans, potatoes, carrots, and beets), finely divided products such as fruit purees and tomato products tend to clog the sieves. A method was developed in which the product is centrifuged, diluted by volume, stained with crystal violet, and counted with the sieving steps eliminated. The proposed method was adopted official first action.

Extraction of Light Filth from Tea: Collaborative Study

1981 ◽  
Vol 64 (2) ◽  
pp. 287-290
Author(s):  
Faith F Lim ◽  
◽  
J Barnett ◽  
A Bright ◽  
M P Chaput ◽  
...  
Keyword(s):  
Sample Preparation ◽  
Collaborative Study ◽  
Tween 80 ◽  
Mineral Oil ◽  
Plant Residue ◽  
Official Method ◽  
Existing Problems ◽  
Aoac Method ◽  
Filter Papers ◽  
Wet Sieving

Abstract The present AOAC method for determining insect and rodent filth in tea is time-consuming because it produces filter papers which are heavy in plant residue and therefore requires long paper-reading times. Anew method for the analysis of light filth in tea was developed to remedy existing problems and to improve recoveries. The method consists of the following steps: sample preparation, wet sieving, dilution with 40% isopropanol, extraction with Tween 80-Na4EDTA-40% isopropanol, flotation with mineral oil-heptane, and trapping off in a Wildman trap flask. In an interlaboratory collaborative study, analysts reported combined insect fragment recoveries of 99.2% for the proposed method and 93.0% for the AOAC method; the same analysts recorded combined rodent hair recoveries of 92.2% for the proposed method and 47.6% for the official method. Average times for reading individual subsamples were 9 min for the proposed method and 27 min for the AOAC method. The proposed method has been adopted official first action.

Identification of Frozen, Cooked Shellfish Species by Agarose Isoelectric Focusing

1983 ◽  
Vol 66 (1) ◽  
pp. 118-122
Author(s):  
Kate Wiggin ◽  
Judith Krzynowek
Keyword(s):  
Isoelectric Focusing ◽  
Official Method ◽  
Modified Method ◽  
Aoac Method ◽  
Aoac Official ◽  
Gel Preparation ◽  
Cooked Meats ◽  
Aoac Official Method

Abstract A modification of the AOAC official method for generic identification of cooked and frozen crabmeat was investigated in an experiment in which the cooked meats of a variety of shellfish were identified. The modification, substituting agarose for polyacrylamide as the gel medium, has many advantages over the official method, including ease of gel preparation, nontoxic reagents, and rapid focusing. Results indicate that the modified method is easier to use and that identifications of cooked shellfish species can be made as readily as with the current AOAC method.

Sign in / Sign up

Export Citation Format

Share Document