scholarly journals The influence of the inside diameter of the coring probe on the chemical composition of lucerne hay samples

2015 ◽  
Vol 44 (5) ◽  
pp. 41-43
Author(s):  
M Van Zyl ◽  
GDJ Scholtz ◽  
HJ Van der Merwe ◽  
R Meeske
Keyword(s):  
Chemical Composition ◽  
Quality Index ◽  
Near Infrared ◽  
Grading System ◽  
Limited Data ◽  
Near Infrared Reflectance ◽  
Inside Diameter ◽  
Small Probe ◽  
Similar Chemical ◽  
Acid Detergent Fibre

The obtaining of a representative sample is crucial for the application of an accurate and uniform lucerne hay grading system in South Africa. There is currently limited data available on the effect of the inside diameter of the coring probe on the chemical composition of the lucerne hay samples. A study was therefore undertaken to determine the influence of the inside diameter of a coring probe on the chemical composition of unground lucerne hay samples using the Near Infrared Reflectance Spectroscopy (NIRS) technique. Ten lucerne bales (total 40), randomly chosen from four different grades (Prime, Grade 1, 2 and 3 according to the National Lucerne Trust quality and grading system), were sampled with both a large probe (35 mm inside diameter and 520 mm long) and a small probe (12 mm inside diameter and 450 mm long). The samples with each probe were taken at approximately the same location in the bale. The samples were analysed with the NIRS for crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF), ash and lignin. The model to calculate the new lucerne quality index (NLQI) from the ADF, ash and lignin, according to the National Lucerne Trust quality and grading scheme was used. Regression analysis revealed a significant relationship (r2) between the results of the large and small probe namely CP = 0.77, ADF = 0.95, NDF = 0.94, ash = 0.92, lignin = 0.87 and NLQI = 0.97. Sampling of lucerne hay with a large and small probe was irrelevant as resulted in similar chemical composition results.Keywords: Analysis grading, New Lucerne Quality Index, NIRS, quality, sampling

scholarly journals Analysis of the Acid Detergent Fibre Content in Turnip Greens and Turnip Tops (Brassica rapa L. Subsp. rapa) by Means of Near-Infrared Reflectance

Foods ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 364 ◽  
Author(s):  
Sara Obregón-Cano ◽  
Rafael Moreno-Rojas ◽  
Ana María Jurado-Millán ◽  
María Elena Cartea-González ◽  
Antonio De Haro-Bailón
Keyword(s):  
Standard Error ◽  
Near Infrared ◽  
Mathematical Treatment ◽  
Second Derivative ◽  
Infrared Reflectance ◽  
Near Infrared Reflectance ◽  
First Derivative ◽  
Acid Detergent Fibre ◽  
Turnip Greens ◽  
Turnip Tops

Standard wet chemistry analytical techniques currently used to determine plant fibre constituents are costly, time-consuming and destructive. In this paper the potential of near-infrared reflectance spectroscopy (NIRS) to analyse the contents of acid detergent fibre (ADF) in turnip greens and turnip tops has been assessed. Three calibration equations were developed: in the equation without mathematical treatment the coefficient of determination (R2) was 0.91, in the first-derivative treatment equation R2 = 0.95 and in the second-derivative treatment R2 = 0.96. The estimation accuracy was based on RPD (the ratio between the standard deviation and the standard error of validation) and RER (the ratio between the range of ADF of the validation as a whole and the standard error of prediction) of the external validation. RPD and RER values were of 2.75 and 9.00 for the treatment without derivative, 3.41 and 11.79 with first-derivative, and 3.10 and 11.03 with second-derivative. With the acid detergent residue spectrum the wavelengths were identified and associated with the ADF contained in the sample. The results showed a great potential of NIRS for predicting ADF content in turnip greens and turnip tops.

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