摘要
Impact bruise damage and quality of‘Gim Ju’guava were investigated for different drop heights and number of drops using fractal image analysis.For the impact test,a stainless-steel metal ball(250 g)was dropped on fruit from three drop heights(0,0.3,0.6 m)either once or five times.Fruit quality was evaluated for impact energy,bruise area(BA),bruise volume(BV),bruise susceptibility,bruise score and pulp color(L*,a*,b*and C values).The fractal dimension(FD)value using fractal image analysis was analyzed at the bruise region.Results showed that five drops(0.3 m)with a high impact energy(3678.75 J)and a single drop(0.6 m)with a low impact energy(1471.50 J)exhibited no significant in BA,BV,bruise score as well as all color values(L*,a*,b*and C).While the FD value of a single drop from 0.6 m had a higher FD value than that of five drops from 0.3 m.It is indicated that FD exhibited a better performance to classify impact bruising level of guava than BA,BV and color parameters.The FD value gradually decreased with increase of storage time and bruise severity.The correlation coefficient(r)values of FD(r=−0.794 and−0.745)between BA and BV were more significant than those L*(r=−0.660 and−0.615)and a*(r=0.579 and 0.473).The coefficient of determination(R^(2))of the polynomial equation in bruised fruit(R^(2)=0.85 to 0.99)was greater than the control(no bruise)(R^(2)=0.80).A higher R^(2)val(0.88 and 0.92)was exhibited at five drops.Interestingly,FD analysis showed greater potential than color measurement to assess bruise impact damage in guava.
