Near Infrared Transmission Spectra of Barley of Malting Grade Represent a Physical-Chemical Fingerprint of the Sample That Is Able to Predict Germinative Vigour in a Multivariate Data Evaluation Model

Birthe Møller
The Royal Veterinary and Agricultural University, Department of Dairy and Food Science, Food Technology, Rolighedsvej 30, DK- 1958 Frederiksberg C, Denmark.
Corresponding author. E-mail: bm@kvl.dk

J. Inst. Brew. 110(1), 18–33, 2004  |   VIEW ARTICLE

ABSTRACT
The physiological and physical-chemical basis of barley germination was studied. Vigour was defined as germination percentage after 24 h and viability as that of 72 h. The barley samples were analysed under germination capacity and energy conditions after harvest and after long time cold storage at 7°C three–six years. These parameters were each correlated by Partial Least Squares Regression (PLSR) to two separate multivariate data sets: a set of ten physical-chemical parameters and to Near Infrared Transmission (NIT) spectra (850–1050 nm). Surprisingly high correlation coefficients for each of these two data sets were obtained especially with vigour, extract (%) and β-glucan in wort (mg/L) when outliers with viability below 92% were removed. Hard, slowly germinating seeds were more resistant to decay in vigour and viability storage than soft seeds. This change could be predicted by PLSR correlations to the two physicalchemical multivariate methods. Vigour was a more sensitive indicator for the ability to store than viability. The steep criterion was also found to have a physical-chemical basis. The results indicate that NIT calibrations can be used to predict vigour in malting grade

Key words:
Malt quality, Near Infrared Transmission spectroscopy, physical-chemical properties, seed imaging analysis, seed viability, seed vigour.

Publication no. G-2004-0317-205 ^©2004 The Institute & Guild of Brewing