Some Links Between and Among Quality Parameters Used in Assessment of Barley Adjuncts for Food Processing
MBAA TQ vol. 45, no. 3, 2008, pp.
268-273 |
VIEW ARTICLE
Reginald C. Agu. The Scotch Whisky Research Institute, Research Avenue North,
Riccarton, Edinburgh, Scotland.
Abstract
Typical barley (adjunct) quick-intake analytical quality parameters, such as
total nitrogen content (near infrared), screenings, thousand corn weight (TCW),
and bushel weight (BW) or specific weight, as well as some experimental quality
parameters (e.g., hot water extract [HWE] used in assessing barley for
acceptance and processing), were evaluated. The links between and among these
quality parameters were also evaluated. The results obtained show that as the
percentage of thin corns increased, the percentage of barley husk also
increased. The high proportion of thin corns also resulted in decreased extract
recovered from barley. Although the inverse relationships between barley
nitrogen and starch contents and between total nitrogen and HWE were confirmed,
these relationships were not as strong as would be expected. These findings
notwithstanding, a very strong positive correlation was found between barley
starch content and HWE, because starch was optimally digested by enzymes
naturally derived from malt and also from commercial enzyme preparations. In
addition, the strong negative correlation found between thin corns (<2.5 mm) and
HWE confirmed the effect that corn size had on barley processing. While BW and
TCW individually showed strong positive relationships with barley HWE, a much
stronger correlation was found between BW and HWE than between TCW and HWE,
suggesting that BW would be preferred to TCW for barley intake. A combination of
screening and BW analysis should provide a stronger indication of the quality of
barley adjunct for acceptance and use in industrial processes.
Keywords: barley, bushel weight, screenings, thousand corn weight
S�ntesis
Se evaluaron diferentes par�metros anal�ticos de calidad de admisi�n r�pida
t�picos para cebada (como adjunto), tales como nitr�geno total (infrarrojo
cercano), cribaje, peso de mil granos (TCW) y peso por �bushel� (BW) o peso
espec�fico, as� como algunos par�metros experimentales de la calidad (e.g.
extracto en agua caliente [HWE] usados en la evaluaci�n de cebada para
aceptaci�n y procesamiento). Tambi�n se evalu� la correlaci�n entre estos
par�metros de la calidad. El porcentaje de c�scara en la cebada aument� al
aumentar el porcentaje de granos finos. Una alta proporci�n de granos finos
result� en una reducci�n del extracto obtenido de la cebada. Aunque se confirm�
la relaci�n inversa entre el contenido de nitr�geno y de almid�n, as� como entre
nitr�geno total y HWE, estas relaciones no eran tan fuertes como se hab�a
esperado. A pesar de estos resultados, s� se consigui� una muy fuerte
correlaci�n positiva entre el contenido de almid�n y HWE, debido a que el
almid�n fue digerido de manera �ptima por enzimas derivados naturalmente de la
malta (como tambi�n de preparaciones enzim�ticas comerciales). La fuerte
correlaci�n negativa entre granos finos (<2.5 mm) y HWE confirm� el efecto que
tiene el tama�o de grano sobre el procesamiento de la cebada. Si bien se
encontr� una relaci�n fuerte positiva de BW y TCW individualmente con el HWE, la
correlaci�n entre BW y HWE fue m�s fuerte que la de TCW y HWE, sugiriendo que BW
ser�a un par�metro m�s preferible que TCW como par�metro de aceptaci�n. Una
combinaci�n de cribaje y an�lisis de BW deber�a proveer una mejor indicaci�n de
la calidad de un adjunto de cebada para su aceptaci�n y uso en procesos
industriales.
Palabras claves: cebada, cribaje, peso de mil granos (TCW), peso por �bushel�
(BW)
