2009 International Nuclear Atlantic Conference - INAC 2009 Rio de Janeiro,RJ, , September27 to October 2, 2009 ASSOCIAÇÃO BRASILEIRA DE ENERGIA NUCLEAR - ABEN ISBN: 978-85-99141-03-8

GAMMA RADIATION EFFECTS ON PEQUI FRUITS ( CAMB.)

Márcio Ramatiz L. Santos1, Valter Arthur1, Jocelem M. Salgado2, Marta H. Fillet Spoto2 and Solange G. Canniatti-Brazaca 2,

1 Lab. Irradiação de Alimentos e Radioentomologia, CENA - Universidade São Paulo Av. Centenário, nº 303 CP 96, CEP: 13400-970, Piracicaba - São Paulo, Brasil [email protected] [email protected]

2 Departamento de Agroindústria, Alimentos e Nutrição, ESALQ-USP Av. Pádua Dias, n° 11, Caixa-Postal: 09, 13418-900 - Piracicaba, SP - Brasil [email protected] [email protected] [email protected]

ABSTRACT

The objective of this work was to evaluate the effects of gamma radiation on characteristics of pequi fruits (Caryocar brasiliense Camb.). Just now, they are gained attention of researchers due their nutritional properties, between then is the pequi fruits. Fruits come from Goiás State was classified, washed and processed to separate the endocarp (edible part) from pericarp. The endocarps were packing in polyethylene bags with 150 g, labeled and submitted to radiation process (0.0, 0.4, 0.6 and 1.0 kGy doses) on multipurpose irradiator located in IPEN/USP. The samples were analyzed to chemical (pH, trititable acidity, °Brix, ratio TSS/TTA, lipids, ash, humidity, protein, soluble and insoluble fiber, total carotenoids and antioxidant activity) and physical properties (loss weight, texture and color). The irradiation process using gamma rays from Co60 was effective to protect pequi fruits in postharvest period.

1. INTRODUCTION

The use of the ionizing radiations has been showing potential effect as auxiliary technology, technique and economically viable, in the reduction of losses post harvest, grains and fruits disinfestation, pathogenic microorganisms controling and increasing fruits and vegetables‟s shelf-life, maturation of fruits, sprout inhibition in tubers and bulbs and maintenance of the nutritional quality [2; 25; 31; 35]. In some countries, the irradiation process is considered as an effective solution in the reduction of the pathogenic microorganisms and it has been recommended as part of a program to increase foods safety of, due to the properties bactericide and fungicidal in the diseases control after crop, being considered as an effective method for fresh fruits [34].

The knowledge of the fruits physiologic behavior, when submitted that technology, it becomes necessary so that it doesn't happen loss in the visual, nutritional and nutraceutical qualities of the same ones. For such purpose, it is necessary to establish the ideal dose for each cultivated , what constitutes a challenge for the food science researchers, because there are several factors that interfering in the results of any post harvest treatment. The chemical and physical effects provoked by the ionizing radiation interaction with the fruit become fundamental when one want to increase the market of irradiated fruits. Now, there is interest renewed in the effects of the foods on the health, and in the potential that constituent rights of the foods can have about the prevention of those diseases, such as heart diseases, cancer, diabetes and osteoporosis, the calls Functional Foods [37].

The purpose of this project was to verify the radiation gamma effects of the Cobalt-60 on pequi fruits, establishing the ideal dose for the conservation. One of the peculiarities of the pequi is its carotenoids composition. Many scientific studies about the role of these components in the human health had showing that there are strong connection with the chronic prevention of degenerative diseases in humans and animals.

2. MATERIAL AND METHOD

2.1. Raw Material

Fruits coming from Goiás State (Brazil) were used, of the October/November 2004 and October/November 2005 crop, acquired in the Ceres city local market. The fruits, in medium ripeness stage, were picked by the "stick system to the foot" what provoked several injuries to the same ones.

Fruits with 110 ± 40 g were classified for the physical injuries presence (cuts, rottenness, burns and bruises), chemistries or microbiologic (presence of mushrooms). The injured fruits were discarded (10% of the total), and selected them, washed in chlorine solution (100 mgL- 1) for 20 minutes and rinsed in chlorinated clean water, been slippery and separating the peel (exocarp) and the putamens (mesocarp more internal endocarp) using stainless knives. The pits were wrapped to vacuous in polyethylene bi-oriented film, labeled with the experimental doses of irradiation and stored in cold camera to -30 ± 2 °C until the analyses. The peels were discarded.

2.2. Fruits Irradiation

In a preliminary stage, was established the maximum dose and in the following stage, the experimental doses. In the first, it was used the doses 3.0; 5.0 and 10.0 kGy, to verify the pequi behavior faced to high irradiation doses in two storage times (1° and 10° day). In the second stage, the smaller experimental doses were used (0.0; 0.4; 0.6 and 1.0 kGy) to establish the ideal dose seeking to conserve the fruits with the smallest modifications in the nutraceuticals properties.

All samples were irradiated in the multi-purpose irradiator of the IPEN-USP with 3.55 kGy/hour (30/03/2005) and 3.04 kGy/hour (23/11/2006) dose rate, stocked at -30°C until the analysis.

2.3. Physiochemical Analyses

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The realized analysis were Ash, Humidity, Soluble and Insoluble Fiber, pH, Color, Ether Extract, Protein, Titratable Total Acidity (TTA), Total Soluble Solids (TSS), Ratio TSS/TTA, Texture, Ascorbic Acid, Total Carotenoids and Antioxidant Capacity.

2.3.1 Ashes

The ashes analysis was accomplished according to AOAC methods [5].The values were expressed in ashes percentage by 100 grams of sample. For this test the pequi fruits were irradiated in the doses 0.0; 0.4; 0.6 and 1.0 kGy.

2.3.2. Humidity

Determined by difference, with the expressed results in % of lost humidity, as procedure described by AOAC [5].

2.3.3. Soluble and insoluble fibers

The soluble and insoluble fiber was determined according to ASP et al. [4] with modifications. The values of soluble and insoluble fiber were expressed in percentage

2.3.4. pH

Determined by pH-meter model Tecnal Tec-3MP, according to norms of the Instituto Adolfo Lutz [26].

2.3.5. Analysis of color

The color was determined in the pequi pulp, by Minolta I colorimeter, model CR-300, using the color system a*, b* and L with opening of 12 mm diameter. The measured color parameters in relation to the white plate (L = 90.23; the * = -2.32; b * = 1.38) were:·L = brightness (0=black and 100=white); a* (-80 until zero = green, from zero to + 100 = red); b* (-100 until zero = blue, from zero to +70 = yellow.

2.3.6. Ether extract (EE) The analysis was accomplished as described by AOAC [5]. The values were expressed in percentage of ethereal extract (%).

2.3.7 Proteins They were accomplished in agreement with the methodologies by AOAC [5]. Results were expressed in protein percentile (%).

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2.3.8. Titratable total acidity (TTA)

TTA was determined according to the Instituto Adolfo Lutz procedures [26]. Three repetitions were made by sample and the results expressed in percentile of citric acid

2.3.9. Total soluble solids (TSS)

Determined by direct reading in refractometer (ATAGO model PZO RR11), corrected in relation to the temperature and citric acid contained in the sample, with results expressed in °Brix [26].

2.3.10. Ratio TSS/TTA

Determined by the quotient between the total soluble solid and total titratable acidity parameters [15].

2.3.11. Texture

Texture was determined with a bench penetrometer, with ferrule of 6.6 mm diameter, through three measurements in the equatorial section in a same fruit, being obtained the pressure requested to the penetration in kg.mm-2 [26].

2.3.12. Ascorbic acid:

Using the Tillmans‟s method, according to IAL procedures [26], with results expressed in mg.100g-1. It was determined immediately after the trituration and filtering of the pulp in mesh dies.

2.3.13. Total carotenoids

The extraction was accomplished with the method described by literature [44], through the extraction with hexane and acetone 1:1. The extract was filtered to vacuous with a Büchner funnel, even color loss, and the pigments containing the carotenoids were washed with distilled water even hexane and acetone were completely removed, and the total carotenoids were determined by spectrophotometry to 470 nm. Chlorophyll A and B was evaluated in agreement with literature [29]. Results were expressed in µg.mL-1.

2.3.14. Antioxidant capacity

The radical stable 2,2-diphenil-1-picril hidrazil (DPPH') it has been widely used to evaluate the capacity of natural antioxidants in kidnapping free radicals [8; 9; 45].

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2.3.15. Statistical analyses

All samples were analyzed three times and results submitted to statistical procedure. The statistical analyses were accomplished being applied the Test F for variance analysis and the Tukey Test to verify the interaction among the variables at p≥0.05 level, being used the SAS STATISTICA software for Windows. In the first experiment they were 4 treatments (doses 0.0; 3.0; 5.0 and 10.0 kGy) and 2 storage times (1° and 10° day) and in the second experiment they were 4 treatments (doses 0.0; 0.4; 0.6 and 1.0 kGy) and 1 day of storage.

3. RESULT AND DISCUSSION

3.1. Humidity, ashes, soluble and insoluble fiber, pH and dry matter In the Table 1 the obtained results of the analyses are expressed for ashes, humidity, soluble fiber, insoluble fiber, pH and matter dries of irradiated pequi.

Table 1: Results for humidity, ashes, soluble fiber, insoluble fiber, pH and matter dries of irradiated pequi (100g-1 of pulp).

Dry Dose Humidity Ashes Soluble Insoluble Matter pH (kGy) (%) (%) Fiber (%) Fiber (%) (%) 0.0 25.53ª 5.77ª 4.42a 8.28a 53.41a 3.69ª 0.4 23.49b 6.15b 5.56a 7.61a 49.63b 3.49b 0.6 24.93a 6.05b 5.00a 7.06b 62.91c 3.43b 1.0 29.43c 5.73ª 5.37a 7.73a 56.71d 3.49b Same letters in the same column indicate that there was not significant difference among the treatments. Different letters in the same column indicate significant difference among treatments (p≥0.05).

The humidity loss varied significantly in 22.98% between the smallest and the largest found value, respectively for the samples treated with the doses 0.4 and 1.0 kGy. The control presented loss of larger humidity than the sample irradiated with dose of 0.4 kGy and equal to the dose of radiation of 0.6 kGy. The sample irradiated with the dose 1.0 kGy presented the largest humidity loss, probably due to the loss of the permeability of the cellular membrane that it facilitated the dehydration. Many authors have been observing alterations in the loss of weight of irradiated fruits, but such phenomenon is dependent of the fruit type (climateric or no climateric), applied dose and storage conditions [13; 19; 39]. According to [7], the tax of lost water, without there being deterioration, is variable for each vegetable and overcoat should not pass of 10%.

Soluble fiber tenor didn't present significant differences. Being added soluble and insoluble fiber is obtained the total fiber, that in this work presented average of 17.13% of total fiber for the control. This value is superior to the found by [20], that they found average of 10.02% in pequi pulp. This difference can be related with the origin of the fruits, crop time, differences in the analysis methodology among others.

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The differences found for ashes, insoluble fiber and matter dries were significant, but very small. Probably these differences are linked to the variations in the humidity loss. It is known that lower gamma radiation doses don't interfere in those parameters.

Significant decrease of the pH values was observed for the samples irradiated in relation to the control, but they didn't differ statistically amongst themselves. It was found small variations in the pH values for the different applied doses in the samples, however, even small variations in that characteristic can represent alterations in the fruits flavor [26]. Those results corroborate with found them in other works in that few variations were verified in the pH. When tangerines were irradiated with doses of 0.5 and 1.0 kGy and stored under temperature of 17oC, the pH of the pulp stayed unaffected for 21 days. [6], the authors studying the effects of the dose of 125 Gy in the mango and papaya pulp, they told that chemical changes were considered very small, with variation in the pH among 0 to 15% after three months of storage. In fruits, the elevation of the pH has been associated with the use of the organic acids, stored in the vacuoles, as respiratory substrate [36].

3.2. Texture, soluble solids, total titratable acidity and ratio SST/ATT

In the Table 2 the results of the texture analyses, soluble solids, total titratable acidity and ratio SST/ATT are shown.

Table 2: Results of the texture analyses, soluble solids, total titratable acidity and ratio SST/ATT of irradiated pequi fruits.

Dose Texture SST ATT SST/ATT (kGy) (Newton g-1) (oBrix) (% Cítric Acid) 0.0 3586a 15.92a 0.63 a 25.27 a 0.4 38.36b 14.25b 0.57 b 25.00 a 0.6 39.89b 14.47 b 0.60 c 24.12 b 1.0 39.37b 14.88 b 0.60 c 24.80 a

Same letters in the same column indicate that there was not significant difference among the treatments. Different letters in the same column indicate significant difference among the treatments (p≥0.05).

The texture had significant increase in the irradiated samples in relation to the control, but it was not significant among the applied doses

The soluble solids tenor of the irradiated samples presented significant decrease in relation to the control, but it was not significant among the used treatments. The SST tenor is a decisive factor in the vegetables ripening.

ATT of the irradiated samples presented significant decrease in relation to the control, but little differed among the applied treatments. These results were opposes to the obtained by [12] in irradiated tomatoes (0.25; 0.5 and 1.0 kGy) that demonstrated significant increase in the levels of ATT and they agree with the data obtained by [17], working with gamma

INAC 2009, Rio de Janeiro, RJ, Brazil. radiation doses (zero, 440, 880 and 1.320 Gy) in 'Gala' apples, where the pulp acidity decreased with the increase of the doses after three storage weeks at 20oC.

The relationship SST/ATT didn't present significant differences, just samples irradiated with 0.6 kGy dose differed of the other treatments. This demonstrates the pequi fruits stability front to the applied doses.

It was found a relationship between the doses of 1 and 5 kGy and the ratio SST/ATT values when they worked with Italy grape, observing increase in the values with the increase of the radiation doses. Those two parameters (SST and ATT) are important in relation to the flavor, and the increase in the fruit sugar tenor is conditioned to the maintenance of the same in the plant, being influenced positively by some cultural practices as the manuring and the green pruning. When it is picked a green fruit, with low total soluble solids tenor, this won't synthesize new sugars, becoming low quality fruit [16].

On the other hand, the high organic acids content presents in green fruits also interferes negatively in the final quality of the product, because they affect the perception of sweetness indirectly. Usually, in all pit fruits, the alterations that happen during the ripening, include the acidity reduction [23]. According to [40], the acid contents tend to decrease and the sugar tenor (soluble solids) to increase with the fruits maturity. The water content and the water loss in fruits during the storage time should be considered always for the interpretation of soluble solids and total titratable acidity values.

3.3. Color analysis

The irradiated pequi fruits presented loss of color compared to the control. The samples were analyzed on 1ft and 10th after the irradiation and the results are shown in the Illustration 1. Significant decreases were observed between the treatments and the control, indicating an effective action of the experimental doses on the color parameter A*, both for the applied dose as for the storage time. The treatment with the dose 5.0 kGy was that demonstrated larger effect of the radiation process, and the sample treated with the dose 3.0 kGy larger effect in relation to the storage time. As the A* value it is one of the ripening indicative, the results indicated a ripening of the fruits during the storage. The sample treated with the dose 10.0 kGy presented smaller effect of the radiation in relation to the applied doses. This demonstrates that the largest applied dose got to inhibit, partly, the pequi ripeness.

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Illustration 1: Color of irradiated pequi for the parameter A*, B* and L in two storage times.

The ripening of fruits happen for the alteration in the A* values indicating changes in the photosynthesis of the pigments, in other words, the chlorophyll degradation and carotenoids synthesis, as well as the oxidation reaction that happen spontaneously. When the carotenoids combine with the air oxygen, with exposing to the light, relative humidity, presence of oxidative enzymes, water activity and metals, the oxidative reactions tend accelerating [33]. The fruit color attribute is the most important, as they are marketed, exposed and sold in supermarkets, fairs, among others. The modifications in the coloration correspond to the main judgement criteria for identification of the fruits ripening, due to the degradation of some pigments and formation of other, as chlorophyll, carotenoids and anthocyanin [14].

For the parameter L, the irradiated fruits presented decrease in relation to the storage time in all treatments, and the brightness presented increase in relation to the applied radiation dose, with that the fruits came with darkness coloration. For the samples treated with the dose 3.0 kGy larger negative variation of the value L was verified between the 1° day of stockpiling and the 10° day. The increase of the brightness indicates the fruits clearance due to applied radiation doses and the brightness decrease due to the storage time indicates the darkening of the fruits due to the pigments degradation of pequi fruits. That same behavior was observed by [46] researching the effects of the gamma radiation in avocados.

The value B* indicates the spectrum from blue (negative values) to yellow (positive values). There was significant decrease of the value b * for all irradiated samples compared to control. The storage time didn't influence significantly on this parameter. The smallest values B* were observed for fruits treated with the dose 10.0 kGy following by those treaties with the dose 3.0 kGy, with superior reduction to 50%. [47] didn't find significant differences for the value B * in the pulp of irradiated Cantaloupe melons (0.0; 0.15; 0.45 and 0.90 kGy).

3.4. Ethereal extract (EE)

The Illustration 2 show the ethereal extract values of the irradiated pequi fruits, where it was verified that the obtained values are superior to found by other authors [51].

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It was verified that the treatments with 3.0 and 5.0 kGy equaled amongst themselves, presenting the smallest averages of EE. Already the treatments with 10.0 kGy were equaled to the control. The smallest EE value was found for 5.0 kGy dose and the largest for 10,0 kGy dose. The control presented EE tenors more than 48% and they were larger than found them by [20; 21; 30; 52]. Great variation is observed in the results due to the differences of cultivating, area, climate, time of the year and analysis method. But, recent studies have been agreeing with the results obtained in this study [51].

Ethereal extract (EE) 48.62a 49 48.26a 48 47 46 44.68b 45 44.18b 44 43 42

41 0.0 3.0 5.0 10.0

Same letters indicate that there was not significant difference among the treatments. Different letters indicate significant difference among the treatments (p≥0.05).

Illustration 2: Ethereal extract values of pequi fruits for applied dose 0.0, 3.0, 5.0 and 10.0 kGy.

Analyzing the EE values of pequi pulp in two maturation states, [20] observed that it was 5.76 g.100g-1 in the fruits no ripe and 10.0 g.100 g-1, in the ripe fruits. Comparing the average values of this work with those obtained by [52], we observed that both are equal, but are higher than 10 g.100 g-1 and 14.83 g.100 g-1 values reported by [10], in fruits collected in Brasília-DF-GO and Luiziânia, respectively. Higher Values (32.55%) were observed by [43] in fruits from Campo Grande - MS. [21] observed that EE pequi content was comparable to the "macaúba", avocado and babassu. Moreover, the pequi oil is considered of excellent quality by its unsaturated fatty acids composition.

3.5. Protein, ascorbic acid, total carotenoids and antioxidant capacity

The Table 3 show protein, ascorbic acid, total carotenoids and antioxidant capacity content of irradiated pequi fruits treated at 0.0, 0.4, 0.6 and 1.0 kGy.

There were not significant differences in the protein tenors between the treatments and the control, but small increase was observed in the irradiated samples. The largest differences were between the control and the 0.4 kGy dose. The values found in this work are larger than

INAC 2009, Rio de Janeiro, RJ, Brazil. found them by other authors [30; 41; 51]. [41] found values among 3.54 and 4.04% of protein in the pequi pulp originating from Luziânia-GO, values these inferior to the found by [52] that found 4.9 and 6.0% in pequis of the same area and Brasilândia-MG, respectively. In fruits coming from other areas, [20] obtained 1.61 g.100 g-1 in fruits from Luiziânia-GO and [10] verified tenors 2.65 g.100 g-1 for fruits come from Brasília-DF. Great variation is observed in the results among different works due to the differences of cultivating researched, area, climate, time of the year, analysis method among others.

Table 3: Results of protein, ascorbic acid, total carotenoids and antioxidant capacity of irradiated pequi fruits.

Analysis 0.0 kGy 0.4 kGy 0.6 kGy 1.0 kGy Dose Protein 7.35a 8.11b 7.70a 7.93a Ascorbic Acid 222.3a 112.6b 39.4c 32.8d Total Carotenoid 16.70a 11.02b 8.92c 7.11d Antioxidant Capacity 92.75a 90.04a 87.87b 82.06c

Same letters in the same line indicate that there was not significant difference among the treatments. Different letters in the same line indicate significant difference among the treatments (p≥0.05).

There was significant effect on the AA tenors compare to control. Significant decrease of the ascorbic acid content in irradiated pequi fruits was observed, proportional to the applied dose. The losses got to 49.85% for the samples treated with the dose 0.4 kGy, 82.28% for treated them with the dose 0.6 kGy and 85.25% for the samples treated with the dose 1.0 kGy, in relation to the control. [49] found similar results working with irradiated orange juice in 0.0 to 7.5 kGy doses, where the decrease of the AA tenor was proportional to the increase of the applied dose. The ascorbic acid values of control are above found them in the [51]. This can be due to the differences as place of fruits origin, time of the year, processing methodology and of analysis among others.

Pequi fruits have a reasonable amount of vitamin C being compared to the banana and superior to the Argentinean apple, to the mango Tommy and to the watermelon. The vitamin C is the most unstable vitamins for being sensitive to the physiochemical agents as the light, the oxygen and the heat. [28] mentioned that the stability loss of the ascorbic acid is consequence of several factors, as the cellular breaking for tissue damage, cut, then as larger the processing, larger the AA losses. Depending on the conditions, AA can act as an antioxidant, as for-oxidizer, as metals quelante, as reducer agent or as oxygen kidnapped reagent. In aqueous systems containing metals, AA can act as a for-oxidizer reducing the metals, which turn more active the oxidation in lower valence state. In the absence of metals, AA is an effective antioxidant in high concentrations. In no-aqueous environment, AA and their esters are not good antioxidants [22]. Ascorbic acid and tocopherol are distributed thoroughly in the human diet and they have been related to the kidnapping of free radicals that provoke damages to the cells [1]. There are evidences that the antioxidants can kidnap or to neutralize the free radicals generated by the food irradiation process. Nutritious as the

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Effective irradiation action was observed with consequent decrease of the total carotenoids content. The losses got to 45.56% obtained in the samples treated with 1.0 kGy dose compare to control. The largest found value was of 16.70 mg.100 g-1 for the experimental control and to smallest for the treatment with 1.0 kGy (7.11 mg.100 g-1). The total carotenoids values of the control are larger than found them by [24; 30; 45]. These results are in agreement with [31], that observed similar effect in irradiated carrots with 0.25, 0.50, 0.75 and 1.0 kGy, where the largest carotenoids losses were proportionally to the applied doses, getting to 31% in the samples treated with the dose 1.0 kGy.

The antioxidant capacity was expressed as percentile of inhibition of radical DPPH oxidation. The processing had significant effect in the antioxidant capacity reduction compared to control, but mainly for 0.6 and 1.0 kGy doses. The reductions in the antioxidant capacity of the irradiated pequi were of 2.92%, 5.26% and 11.52% for the samples treated with the doses 0.4 kGy, 0.6 kGy and 1.0 kGy, respectively. The values presented in this study corroborate with found them by [45] they studied the antioxidant activity of Brazilian savannah fruits, among them the pequi, and they found for the concentration of 2500 µg.mL-1 an antioxidant activity of 90% for the ethanolic extract and 78% for the aqueous extract. The small difference found between this work and our study if it owes, probably, at the time between the obtaining of the fruits and their analyses. [27] They found similar effect in the decrease antioxidant activity of Nigella sativa when irradiated with doses from 2 to 16 kGy, and for some experimental solvents, it was found the increase of the antioxidant activity with the increase of the applied dose. [50] investigated the effects of the gamma radiation (5.0 to 30.0 kGy) in the antioxidant activity of dehydrated black pepper and they observed significant decrease for all the applied doses.

The levels of 92.75% of the antioxidant capacity of the experimental control are in agreement with found by [42] that investigated the capacity antimicrobial, anti leishmaniasis and antioxidant of pequi fruits. [45] Verified the excellent antioxidant capacity of the pequi fruits and of other fruits of the Brazilian savannah, detaching its economical importance for the pharmaceutical and cosmetics industries.

4. CONCLUSIONS

After analyses of the results, it is inferred that:

The Cobalt-60 gamma radiation was effective in the maintenance of the pequi fruits nutritional properties.

The pequi didn't support high doses of radiation, because dose above 1.0 kGy faded and had darkened the fruits turning them opaque, what makes unfeasible them commercially, tends in view that the consumer buys this fruit being based, usually, in the coloration yellow-orange characteristic of that fruit.

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The total carotenoids were affected, proportionally, for the increase of the radiation doses to applied treatments, and between the doses 0.4 and 0.6 kGy are the best results with the smallest losses.

The antioxidant capacity of the irradiated pequi fruits decreased, proportionally, to the increase of applied dose. The main components with antioxidant activity affected were, mainly, the vitamin C content and total carotenoids.

The pequi fruits irradiation process is a viable technology that it showed promising results in conservation, being recommended gamma radiation doses between 0.4 and 0.6 kGy.

ACKNOWLEDGMENTS

Acknowledgments to CENA/USP and EASLQ/USP for release the laboratories and to CAPES by financial support.

REFERENCES

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9. BRAND-WILLIAMS, W.; CUVELIER, M. E.; BERSET, C. Use of a free radical method to evaluate antioxidant activity. Lebensmittel - Wissenschaft und Technologie, Oxford, v. 28, p. 25-30, 1995. 10. CARVALHO, M.C.; BURGER, O.N. Contribuição ao estudo do pequi de Brasília. Brasília: SPS, 1960. 15 p. (Coleção Estudo e Pesquisa Alimentar, 50). 11. CARVALHO, P.R.N.; RODRIGUEZ-AMAYA, D.; COLLINS, C.H.; CARVALHO, C.R.L. Determinação de Carotenóides Provitamina A por Cromatografia Líquida de Alta Eficiência (CLAE). Coletânea do ITAL, Campinas, v. 21, n. 2, p. 317-328, 1991. 12. CASTRICINI, A.; MEDEIROS, S.F.; CONEGLIAN, R.C.C.; VITAL, H.C. Uso da radiação gama na conservação pós-colheita do tomate de mesa (Lycopersicum esculentum MILL.): fruto “de vez”. Revista Universidade Rural. Série Ciências da Vida, Seropédica, v. 22, n. 2, p. 223-229, 2002. Suplemento. 13. CHEFTEL, J.C.; CHEFTEL, H.; BESANÇON, P. Metodos de conservacion. Tratamiento por la radiaciones ionizantes. In: CHEFTEL, H.; CHEFTEL, J.C. Introducción a la bioquímica y tecnologia de los alimentos. Zaragoza: Acribia, 1992. v. 2, p. 277-284. 14. CHITARRA, M. I. F.; CHITARRA, A. B. Pós-colheita de frutas e hortaliças: fisiologia e manuseio. 2. ed. Lavras: UFLA, 2005. p. 273-275; 541-753. 15. CHITARRA, M.I.F.; CHITARRA, A.B. Pós-colheita de frutos e hortaliças. Lavras: FAEPE, 1990. 293 p. 16. DOMARCO, R. E.; SPOTO, M. H. F.; BLUMER, L.; WALDER, J. M. M. Sinergia da radiação ionizante e do aquecimento na vida de prateleira da uva „Itália. Scientia Agricola, Piracicaba, v. 56, n. 4, p. 981-986, 1999. 17. FAN, X.; MATTHEIS, J.P. 1-Methylcyclopropene and storage temperature influence responses of `Gala' apple fruit to gamma irradiation. Postharvest Biology and Technology, Amsterdam, v. 23, n. 2, p. 143-151, 2001. 18. FAO/IAEA/WHO. Joint FAO/IAEA/WHO study group on high dose irradiation (Wholesomeness of food irradiation with doses above 10 kGy). Geneve: WHO, 1999. 19. FEITOSA, H.O.; CONEGLIAN, R.C.C.; CASTRICINI, A.; SOUSA, C.M.; MARTINS, C.M.; VITAL H.C. efeito da radiação gama e de fitorregulador na fisiologia pós-colheita de mamão (Carica papaya L.). Revista Universidade Rural. Série Ciências da Vida, Seropédica, v. 25, n. 1, p. 6-11, 2005. 20. FERREIRA, F.R.; BIANCO, S.; DURIGAN, J.F.; BELINGIERE, P.A. Caracterização física e química de frutos maduros de pequi. In: CONGRESSO BRASILEIRO DE FRUTICULTURA, 9., 1987, Campinas. Anais... Campinas: SBF, 1988. 21. FRANCO, G. Tabela de composição química dos alimentos. 8. ed. São Paulo: Atheneu, 1989. p. 5-8. 22. FRANKEL, E.N. Antioxidant in lipid foods and their impact on food quality. Food Chemistry, Barking, v. 57, p. 51–55, 1996. 23. GIRARDI, C.L.; ROMBALDI, C.V. Sistema de produção de pêssego de mesa na região da Serra Gaúcha. Bento Gonçalves: Embrapa Uva e Vinho, 2003. (Sistema de Produção, 3). Disponível em: http://sistemasdeproducao.cnptia.embrapa.br/ FontesHTML/Pessego/PessegodeMesaRegiaoSerraGaucha/index.htm. Acesso em: abril 2008. 24. GODOY, H. T.; RODRIGUEZ-AMAYA, D. B. Occurrency of cis-Isomers of provitamin A in brazillian fruits. Journal Agricultural Food Chemistry, Easton, v. 42, p. 1306-1313, 1994.

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25. HAGENMAIER, R.D.; BAKER, R.A. Microbial population of shredded carrot in modified atmosphere packaging as related to irradiation treatment. Journal of Food Science, Chicago, v. 63, n. 1, p. 162-164, 1998. 26. INSTITUTO ADOLFO LUTZ. Normas analíticas do Instituto Adolfo Lutz. 3. ed. São Paulo, 1985. v. 1, 533 p. 27. KHATTAK, K. F.; SIMPSON, T.J.; IHASNULLAH. Effect of gamma irradiation on the extraction yield, total phenolic content and free radical-scavenging activity of Nigella sativa seed. Food Chemistry, Barking, v. 110, p. 967-972, 2008. doi:10.1016/j.foodchem.2008.03.003. 28. KLEIN, B.P. nutritional consequences of minimal processing of fruits and vegetables. Journal of Food Quality, Westport, v. 10, p. 179-193, 1987. 29. LICHTENTHALER, H. K. Chlorophylls and carotenoids: pigments of photosynthetic biomembranes. Methods in Enzymology. Plant Cell Membranes, London, v. 148, n. 22, p. 350-373, 1987. 30. LIMA, A.; SILVA, A.M.O.; TRINDADE, R.A.; TORRES, R.P.; MANCINI- FILHO, J. Composição química e compostos bioativos presentes na polpa e na amêndoa do pequi (Caryocar brasiliense Camb.). Revista Brasileira de Fruticultura, Jaboticabal-SP, v. 29, n. 3, p. 695 – 698, dezembro, 2007. 31. LIMA, K.S.C.; GROSSI, J.L.S.; LIMA, A.L.S.; ALVES, P.F.M.P.; CONEGLIAN, R.C.C.; GODOY, R.L.O.; SABAA-SRUR, A.U.O. Efieto da irradiação ionizante γ na qualidade qualidade pós-colheita de cenouras (Daucos carota L.) cv Nantes. Ciência e Tecnologia de Alimentos, Campinas, v. 21, n. 2, p. 202-208, 2001. 32. LIMA, K.S.C.; LIMA, A.L.S.; FREITAS, L.C.; DELLA-MODESTA, R.C.; GODOY, R.L.O. Efeitos de baixas doses de irradiação nos carotenóides majoritários em cenouras prontas para o consumo. Ciência e Tecnologia de Alimentos, Campinas, v. 24, n. 2, p. 183-193, 2004. 33. LIMA, V. L. A. G. de; MÉLO, E. A.; LIMA, D. E. S. Fenólicos e carotenóides totais em pitanga. Scientia Agricola, Piracicaba, v. 59, n. 3, p. 447-450, 2002. 34. LODGE, N.; HOGG, M. G.; FLETCHER, G. C. Gamma-irradiation of frozen kiwifruit pulp. Journal of Food Science, Chicago, v. 50, p. 1224-1226, 1985. 35. MATIN, M. A.; BHUIYA, A. D.; AMIN, M. R.; MALEK, M. A. Irradiation of onions, pulses and dried fish: process control, storage, test marketing and economic analysis of the process. Vienna: IAEA, 1996. p. 19-49. (TECDOC, 871). 36. MEDLICOTT, A. P.; JEGER, M. J. The development and application of postharvest handling treatment to manipulate ripening in mangoes. In: PINSLEY, R. T.; TUCKER, R. T. Mangoes: a review. London: Commonwealth Science Council, 1987. p. 56-77. 37. MILNER, J. A.; RIVLIN, R. S. Recent advances on the nutritional effects associated with the use of garlic as a supplement. Introduction. Journal of Nutrition, Bethesda, v. 131, n. 3, p. 950S-951S, 2001. 38. MOLINS, R. A. Food irradiation: principles and applications. New York: Wiley- Interscience, 2001. p. 213-240. 39. O´BEIRNE, D. Irradiation of fruits and vegetables: applications and issues. Professional Horticulture, Oxford, v. 3, p. 12-19, 1989. 40. OLIVAS, G. I.; BARBOSA-CÁNOVAS, G. V. Edible coatings for fresh-cut fruits. Critical Reviews in Food Science and Nutrition, Boca Raton, v. 45, n. 7, p. 657- 670, 2005.

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41. OLIVEIRA, M. N. S.; GUSMÃO, E.; LOPES, P. S. N.; SIMÕES, M. O. M.; RIBEIRO, L. M.; DIAS, B. A. S. Estádio de maturação dos frutos e fatores relacionados aos aspectos nutritivos e de textura da polpa de pequi (Caryocar brasiliense Camb.). Revista Brasileira de Fruticultura, Jaboticabal, v. 28, n. 3, p. 380-386, 2006. 42. PAULA-JUNIOR, W.; ROCHA, F.H.; DONATTI, L.; FADEL-PICHETH, C.M.T.; WEFFORT-SANTOS, A.M. Leishmanicidal, antibacterial, and antioxidant activities of Caryocar brasiliense Cambess leaves hydroethanolic extract. Revista Brasileira de farmacognosia, João Pessoa, v. 16, p. 625-630, 2006. Suplemento. 43. RAMOS, M. I. L. Desidratação do piqui (Caryocar brasiliense Camb.): avaliação do processo através dos teores de carotenóides totais. 1987. 116 f. Dissertação (Mestrado)- Faculdade de Ciências Farmacêuticas, Universidade de São Paulo, São Paulo, 1987. 44. RODRIGUEZ, D. B.; RAYMOND, L. C.; LEE, T.; SIMPSON, K. L.; CHICHESTER, C. O. Carotenoid pigment changes in ripening Momordica charantia fruits. Annals of Botany, Oxford, v. 40, p. 615-624, 1976. 45. ROESLER, R.; MALTA, L. G.; CARRASCO, L. C.; HOLANDA, R. B.; SOUSA, C. A. S.; PASTORE, G. M. Atividade antioxidante de frutas do Cerrado. Ciência e Tecnologia de Alimentos, Campinas, v. 27, n. 1, p. 53-60, 2007. 46. SILVA, L. K. F. Uso da radiação gama do cobalto-60, para controlar a broca-do- abacate Stenoma catenifer Walsingham, 1912 (Lepidoptera: Elachistidae) e seus efeitos na qualidade do fruto de Persea americana (Miller) (Lauraceae). 2004. 99 f. Tese (Doutorado) - Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, 2004. 47. SIQUEIRA, A. A. Z. C. Utilização da radiação gama e melões Cantaloupe (Cucumis melo L. var. Cantaloupensis) como técnica de conservação pós-colheita. 2007. 108 f. Tese (Doutorado) - Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, 2007. 48. SIQUEIRA, M. I. D.; GERALDINE, R. M.; QUEIROZ, K. S.; TORRES, M. C. L. T.; SILVEIRA, M. F. A. Conserva de pequi. Goiânia: s.l., 1997. 22 p. (Manual Técnico, 2). 49. SPOTO, M. H. F. Radiação gama na conservação do suco concentrado de laranja: características físicas, químicas e sensoriais. 1988. 91 f. Dissertação (Mestrado) – Escola Superior de Agricultura “Luiz de Queiroz” - Universidade de São Paulo, Piracicaba, 1988. 50. SUHAJ, M.; RÁCOVÁ, J.; POLOVKA, M.; BREZOVÁ, V. Effects of gamma irradiation on antioxidant activity of black pepper (Piper nigrum L.). Food Chemistry, Barking, v. 97, n. 4, p. 696-704, 2006. 51. TABELA brasileira de composição de alimentos. Versão II. 2. ed. Campinas: NEPA, UNICAMP, 2006. 113 p. 52. VILELA, G. F. Variações em populações naturais de Caryocar brasiliense Camb. (): fenológicas, genéticas e de valores nutricionais de frutos. 1998. 88 f. Dissertação (Mestrado em Engenharia Florestal) - Universidade Federal de Lavras, Lavras, 1998.

INAC 2009, Rio de Janeiro, RJ, Brazil.