**2.6 Color**

The colorimeter Minolta CR-200 b was used, previously calibrated in White according to pre-determined standards, according to (Bible and Singha, 1993).

Three values of chroma were evaluated: a\*, b\* and L (Figure 4). The value a\* characterizes the color from the red (+a\*) to the green (-a\*); the value b\* indicates the color from the

Fig. 4. Representation of a solid color in the space color L\* a\* b\* (Konica Minolta, 2011)

The Effects of Gamma Radiation in Nectar of Kiwifruit (*Actinidia deliciosa*) 315

0.5 kGy. For the control the nectar irradiated at 1.0 kGy was found the same amount of

Control 16.70±0.011b2 8.8±0.11b 3.5±0.1b 108.0±0.01a

0.5 16.60±0.01c 9.2±0.1a 3.2±0.1a 108.0±0.01a

1.0 16.70±0.01b 8.2±0.1c 3.0±0.1c 54.0±0.01b

2.0 16.80±0.01a 8.8±0.1b 3.0±0.1d 54.0±0.01b

Table 1. Variation of Brix (degrees Brix), acidity titled, pH and ascorbic acid of the kiwi

Statistical differences were verified among the treatments, indicating that the irradiation influenced this parameter, confirmed in a study accomplished by Spoto and Veruna-Bernardi (2002) in orange juice irradiated in several doses an increase was observed in the

In the research they found values above the literature for fruit the kiwi nectar needs sucrose addition to reach to 15 ºBrix (ideal to nectar) what allowed an ideal palate for the

The obtained variations of the titled acidity (% of citric acid) of the kiwi nectar irradiated at

Is possible to observed through of the Table 1, that the dose of (0.5 kGy) which received the smallest radiation presented an increase in the acidity tenor indicating that the treatment influenced for the increase following by the control that did not differ statistically of the doses of 2.0 kGy and 1.0 kGy presented a smaller acidity among the analyzed samples.

The tenors of total acids vary from 1.0-1.5% being the citric acid the principal. In this work

Study accomplished by Leite; Gêa; Arthur; 2006, showed tenors of total acids for the sample non- irradiated 16.04%, and for the sample irradiated 16.58 and 15.85% for the doses of 1.0

These values differ to the values found in this work; what could be explained by the degree

(%) pH Ascorbic acid

soluble solids, in other words, the same value for ºBrix.

Dose ºBrix Acidity titled

2 medias with different word(s) in the vertical they differ significantly

nectar irradiated to 0.5; 1.0; 2.0kGy and, in the control

consumption in terms of sugar percentage

doses of: 0 (control); 0.5; 1.0; 2.0 kGy, are in Table 1.

were found values above the one of the literature for kiwi.

1 Media ± Standard Deviation

tenor of soluble solids.

**3.2 Titled acidity** 

and 2.0 kGy, respectively.

of fruit maturation.

at the level of 5%.

yellow (+b\*) to the blue (-b\*). The value L determine the light ranging from white (L=100) to black (L=0). The chroma is the ratio between a\* and b\*, where the real color can be obtained. Hue-Angle is the angle between a\* and b\*, indicating the color saturation of the analyzed object.

To estimate chroma value, the following formula was adopted (1) and to estimate the Hue-Angle, formula (2) (Estevez & Cava, 2004).

$$\mathbf{C} = \sqrt{\left(\mathbf{a}\mathbf{2} + \mathbf{b}\mathbf{2}\right)}\tag{1}$$

$$\mathbf{H}^{\mathrm{o}} \mathbf{\overline{a}r} \mathbf{c} \mathbf{p} \mathbf{g} \ \mathbf{b}^{\*}/\mathbf{a}^{\*} \tag{2}$$

#### **2.7 Sensorial analyses**

Sensory acceptances of the irradiated and non-irradiated kiwi nectar were done with 41 non-expert panelists.

It was requested the participation of healthy adults (from 18 to 50 years old) of both sexes who declared kiwi's consumers and, that did not present any reaction concerning the consumption of the same and the same ones manifested its consent. They were selected by aleatoric base. The sensorial analysis was constituted by color; smell; flavor; texture and overall acceptance.

Panelists were instructed to evaluate each attribute using a nine-point hedonic scale ranging from "extremely dislike" to "extremely like". Test of acceptability of hedonic scale was used, since it is necessary to know the consumers "affectionate status" regarding the product inferring the preference, in other words, the most favorite samples are the more accepted and vice versa. The scales were balanced once they present equal number of positive and negative categories (1 to 9) (Ferreira, 2000).

About 50 ml of each kiwi nectar treatment were given individually to the panelists and a three digit code was used for the sample. Mineral water was provided to wash the oral cavity after tasting each treatment

To red light was used to mask possible induction by the color in others attributes (Ferreira, 2000).

#### **2.8 Statistical analyses**

The experimental design was complete randomized with three replications. Results were analyzed (ANOVA) using the F test, and mean comparisons were tested based on Tukey (p<0,05) using SAS (Statistical Analysis System, 1996).

### **3. Results and discussion**

#### **3.1 Tenor of soluble solids**

The obtained variations of Brix (Brix degrees) of the kiwi nectar irradiated at doses of: 0 (control); 0.5; 1.0; 2.0 kGy are in Table 1.

Is possible to observe in agreement with the Table 1, that the treatment which received radiation dose of 2.0 kGy presented a larger amount of soluble solids, following by dose of


0.5 kGy. For the control the nectar irradiated at 1.0 kGy was found the same amount of soluble solids, in other words, the same value for ºBrix.

1 Media ± Standard Deviation

314 Gamma Radiation

yellow (+b\*) to the blue (-b\*). The value L determine the light ranging from white (L=100) to black (L=0). The chroma is the ratio between a\* and b\*, where the real color can be obtained. Hue-Angle is the angle between a\* and b\*, indicating the color saturation of the analyzed

To estimate chroma value, the following formula was adopted (1) and to estimate the Hue-

C=√(a2+b2) (1)

Sensory acceptances of the irradiated and non-irradiated kiwi nectar were done with 41

It was requested the participation of healthy adults (from 18 to 50 years old) of both sexes who declared kiwi's consumers and, that did not present any reaction concerning the consumption of the same and the same ones manifested its consent. They were selected by aleatoric base. The sensorial analysis was constituted by color; smell; flavor; texture and

Panelists were instructed to evaluate each attribute using a nine-point hedonic scale ranging from "extremely dislike" to "extremely like". Test of acceptability of hedonic scale was used, since it is necessary to know the consumers "affectionate status" regarding the product inferring the preference, in other words, the most favorite samples are the more accepted and vice versa. The scales were balanced once they present equal number of positive and

About 50 ml of each kiwi nectar treatment were given individually to the panelists and a three digit code was used for the sample. Mineral water was provided to wash the oral

To red light was used to mask possible induction by the color in others attributes (Ferreira,

The experimental design was complete randomized with three replications. Results were analyzed (ANOVA) using the F test, and mean comparisons were tested based on Tukey

The obtained variations of Brix (Brix degrees) of the kiwi nectar irradiated at doses of: 0

Is possible to observe in agreement with the Table 1, that the treatment which received radiation dose of 2.0 kGy presented a larger amount of soluble solids, following by dose of

Hº=arcpg b\*/a\* (2)

object.

Angle, formula (2) (Estevez & Cava, 2004).

negative categories (1 to 9) (Ferreira, 2000).

(p<0,05) using SAS (Statistical Analysis System, 1996).

cavity after tasting each treatment

**2.8 Statistical analyses** 

**3. Results and discussion 3.1 Tenor of soluble solids** 

(control); 0.5; 1.0; 2.0 kGy are in Table 1.

**2.7 Sensorial analyses** 

non-expert panelists.

overall acceptance.

2000).

2 medias with different word(s) in the vertical they differ significantly at the level of 5%.

Table 1. Variation of Brix (degrees Brix), acidity titled, pH and ascorbic acid of the kiwi nectar irradiated to 0.5; 1.0; 2.0kGy and, in the control

Statistical differences were verified among the treatments, indicating that the irradiation influenced this parameter, confirmed in a study accomplished by Spoto and Veruna-Bernardi (2002) in orange juice irradiated in several doses an increase was observed in the tenor of soluble solids.

In the research they found values above the literature for fruit the kiwi nectar needs sucrose addition to reach to 15 ºBrix (ideal to nectar) what allowed an ideal palate for the consumption in terms of sugar percentage
