Standardised skewness and standardised kurtosis analyses
were made to verify normal distribution of the data. Multiple sample
comparison was conducted to evaluate significant differences
among samples by analysis of variance (ANOVA) and multiple
range tests. Fisher’s least significant differences (LSD) test was used
to describe means with 95% confidence (P < 0.05). All statistical
analyses were performed using Statgraphics Centurion 16 (Statistical
Graphics Corporation, UK).