Extraction of Light Filth from Canned Green Leafy Vegetables: Collaborative Study

1979 ◽  
Vol 62 (3) ◽  
pp. 600-601
Author(s):  
Russell G Dent ◽  
Jack L Boese
Keyword(s):  
Plant Material ◽  
Collaborative Study ◽  
Excessive Amount ◽  
Leafy Vegetables ◽  
New Method ◽  
Official Method ◽  
Green Leafy Vegetables

Abstract The official first action method, 44.108, for the extraction of light filth from whole or chopped canned greens specifies a waterheptane flotation that results in the flotation of an excessive amount of interfering plant material and in low recoveries. A new method has been developed using a 40% isopropanol-watermineral oil flotation. The new method yielded a decreased amount of plant material and 84.9% recovery of the aphid spike compared with 42.5% recovery of the spike by the official method. The new method has been adopted as official first action to replace the existing method, except for broccoli.

Collaborative Study of a New Method for the Extraction of Aphids, Thrips, Mites, and Flies from Frozen Green Leafy Vegetables

1974 ◽  
Vol 57 (3) ◽  
pp. 693-695
Author(s):  
Mary T Miller
Keyword(s):  
Sodium Sulfate ◽  
Collaborative Study ◽  
Mineral Oil ◽  
Leafy Vegetables ◽  
New Method ◽  
Green Leafy Vegetables

Abstract A method, which consisted of mixing various frozen green leafy vegetables with dilute sodium sulfate and mineral oil followed by flotation in a Wildman trap flask or Corning percolator, was tested by 12 collaborators. Satisfactory results were obtained and the method has been adopted as official first action.

Extraction of Light Filth from Ground Nutmeg: Collaborative Study

1979 ◽  
Vol 62 (3) ◽  
pp. 595-596
Author(s):  
Joel J Thrasher
Keyword(s):  
Plant Material ◽  
Collaborative Study ◽  
Mineral Oil ◽  
New Method ◽  
Official Method ◽  
Additional Problem

Abstract The official method for extracting light filth from ground nutmeg, 44.116, gives variable recoveries of filth elements and results in large amounts of interfering plant material in the light filth extraction. A new method has been developed using a chloroform pretreatment for heavy filth followed by a water-40% isopropanol- mineral oil flotation of light filth. A comparison of the methods in the collaborative study showed a higher recovery of insect fragments, 90.6 vs. 65.2%, and of rodent hairs, 86.5 vs. 66.5%, for the new method over the present official first action method, 44.116. Frothing, an additional problem with the official method, has been reduced by the new method. The new method has been adopted as official first action to replace the existing method.

Collaborative Study of a New Method for Extraction of Light Filth from Reconditioned (Coarsely Ground) Nutmeg

1971 ◽  
Vol 54 (3) ◽  
pp. 575-578
Author(s):  
Alberto W Vazquez
Keyword(s):  
Collaborative Study ◽  
Mineral Oil ◽  
New Method ◽  
Official Method ◽  
Collaborative Testing

Abstract A new method has been developed for extraction of light filth from coarsely ground nutmeg. Nutmeg tissue is defatted by 3 successive 10 min extractions with boiling CHCI3, after which the solvent is removed by aspiration and an isopropanol rinse. Following sieving on a No. 230 sieve and a brief deaeration and hydrolysis step in acidified boiling 60% ethanol-CaCl2, light filth elements are extracted with mineral oil from the 60% ethanol-CaCl2 mixture. Collaborative testing of the proposed method yielded satisfactory recoveries of added light filth elements. The official method for ground spices, 40.106(b), was compared in a collaborative study with the proposed method for the analysis of ground nutmeg and mace. Results were encouraging, but further study is indicated. The method as described for reconditioned nutmeg has been adopted as official first action.

Collaborative Study of a New Method for the Extraction of Light Filth from Ground Coffee

1972 ◽  
Vol 55 (1) ◽  
pp. 57-59
Author(s):  
Joel J Thrasher
Keyword(s):  
Hydrogen Peroxide ◽  
Carbon Tetrachloride ◽  
Collaborative Study ◽  
Mineral Oil ◽  
New Method ◽  
Official Method ◽  
Peroxide Bleaching ◽  
Filter Papers ◽  
Analytical Time ◽  
Ground Coffee

Abstract A collaborative study has been completed on a new method for light filth in ground coffee. The sample is defatted with chloroform, dried, and boiled in water; isopropanol is added and the sample is boiled again. Light filth is trapped off with mineral oil from a hot solution. The method yields better recoveries of insect fragments and rodent hairs than the official method. Other advantages are less analytical time, cleaner filter papers, and elimination of the use of carbon tetrachloride. It is recommended that the method be adopted as official first action to replace 40.007(b) for the isolation of light filth from ground coffee and that the hydrogen peroxide bleaching technique described earlier be adopted as a procedure to replace the sodium hypochlorite technique described in 40.006.

scholarly journals PLS calibration to resolve overlapping peaks of lutein and zeaxanthin in vegetable samples by LC

2012 ◽  
Vol 30 (No. 4) ◽  
pp. 358-363 ◽  
Author(s):  
D. González-Gómez ◽  
M. Lozano ◽  
A.M. Fernández-León ◽  
M.F. Fernández-León ◽  
F. Cañada-Cañada
Keyword(s):  
Plant Material ◽  
Chromatographic Method ◽  
Leafy Vegetables ◽  
Red Pepper ◽  
Chromatographic Peak ◽  
Green Pepper ◽  
Green Leafy Vegetables ◽  
Vegetable Samples ◽  
Overlapping Peaks ◽  
Absorbance Spectra

The chromatographic method in combination with a Partial Least Squares (type PLS-1) chemometric tool was developed to analyse simultaneously the carotenoid compounds, lutein and zeaxanthin. Both analytes appear together in the same chromatographic peak. Different calibration matrices were done using the absorbance spectra, obtained in the peak apex. The method was successfully applied to plant material such as cabbage, broccoli, red pepper, yellow pepper, and green pepper. The higher content of lutein was found in the green leafy vegetables such as broccoli and cabbage. On the other hand, zeaxanthin was only found in pepper, with the highest concentration having been found in red pepper.  

Total Nitrogen in Fertilizers

1968 ◽  
Vol 51 (4) ◽  
pp. 851-857
Author(s):  
Paul R Rexroad ◽  
Gary F Krause
Keyword(s):  
Total Nitrogen ◽  
Collaborative Study ◽  
New Method ◽  
Official Method ◽  
Powder Method ◽  
Catalyst Powder

Abstract A three-laboratory collaborative study was made of the comprehensive nitrogen method and the new Raney catalyst powder method for total nitrogen in fertilizers. Both methods worked quite well and, with minor modifications, they should provide the basis for a broader collaborative stvidy to provide an official method for total nitrogen in fertilizer applicable to all samples. The limitations of method 2.045 are reviewed and a rephrasing of the official applications of the method is recommended. Further work is recommended toward adoption of a new method and possible deletions or change of status in current official methods.

Total Solids in Processed Vegetables

1964 ◽  
Vol 47 (3) ◽  
pp. 492-500
Author(s):  
Frank C Lamb
Keyword(s):  
Sample Size ◽  
Diatomaceous Earth ◽  
Collaborative Study ◽  
New Method ◽  
Official Method ◽  
Total Solids ◽  
Sources Of Error ◽  
Vegetable Products ◽  
The Individual

Abstract A method was developed for total solids in processed vegetable products, involving diluting with diatomaceous earth, predrying by any of three procedures, and final drying in vacuo for 2 hours at 69-71°. The new method was found to give lower results than the official method on all products tested except pork and beans and baked beans. In a collaborative study by 17 analysts in 9 laboratories, the new method was slightly more precise than the official method, but its main advantage was in providing greater flexibility in sample size and predrying conditions, and in requiring less time for an analysis. The major sources of error in both methods appeared to be deficiencies in the vacuum ovens used and lack of skill of the individual analysts.

Collaborative Study of a Method for the Extraction of Light Filth from Ground Chicory

1971 ◽  
Vol 54 (3) ◽  
pp. 571-572
Author(s):  
J J Thrasher
Keyword(s):  
Collaborative Study ◽  
New Method ◽  
Official Method ◽  
Average Recovery ◽  
Paraffin Oil ◽  
Filter Papers ◽  
Wet Sieving

Abstract Collaborative results are presented on a new method for light filth in ground chicory. A comparison of the new method and the official method, 40.007(b), indicates that recoveries of spiked larvae and adult insects were approximately equal for the 2 methods. However, average recovery of rodent hairs by the proposed method was 86% while rodent hair recovery by the official method was 55%. The new method utilizes detergent digestion and wet sieving followed by flotation with paraffin oil from 40% isopropanol. It is less time consuming to perform and cleaner filter papers are obtained. The new method has been adopted as official first action.

Enumeration of Coliforms in Nonfat Dry Milk and Canned Custard by Hydrophobic Grid Membrane Filter Method: Collaborative Study

1983 ◽  
Vol 66 (4) ◽  
pp. 897-904
Author(s):  
Phyllis Entis ◽  
◽  
B W Ciebin ◽  
V Gipson ◽  
M Grahn ◽  
...  
Keyword(s):  
Membrane Filter ◽  
Collaborative Study ◽  
Reference Method ◽  
New Method ◽  
Filter Method ◽  
Official Method ◽  
Random Errors ◽  
Dry Milk ◽  
Membrane Filter Method ◽  
Nonfat Dry Milk

Abstract A collaborative study was conducted in 14 laboratories to evaluate the performance of the hydrophobic grid membrane filter method against the official final action method, 46.016, for enumeration of colif orms in foods. Twelve artificially contaminated samples of nonfat dry milk and canned custard were analyzed by each laboratory. The random errors (Sr2) associated with the hydrophobic grid membrane filter method were significantly lower than those of the official method, and the counts obtained by the new method fell within the 95% confidence interval of the reference method. The colif orm counts obtained by tiie hydrophobic grid membrane filter method did not differ significantly from those obtained by the reference method as measured by a 3-way analysis of variance. The new method has been adopted official first action.

Collaborative Study of an Acid Autoclave Method for Mineral Oil Extraction of Light Filth from Spaghetti and Macaroni

1969 ◽  
Vol 52 (3) ◽  
pp. 463-465
Author(s):  
Joel J Thrasher
Keyword(s):  
Collaborative Study ◽  
Mineral Oil ◽  
Oil Extraction ◽  
New Method ◽  
Official Method ◽  
Plain Weave ◽  
Filter Papers ◽  
Wet Sieving ◽  
Better Than

Abstract A method for the extraction of light filth from alimentary pastes based on rapid autoclaving of acidified samples, wet sieving on a No. 230 plain weave sieve, and heating the sieve retainings in an acidic mineral oil mixture is described. This new method is faster and results in higher and more reproducible recoveries than method 36.025. Recoveries were equal or better than those achieved by the official method, and the filter papers were cleaner.

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