Impact of Infestation Different Percentages With Olive Fruit Fly, Bactrocera oleae (Rossi) ( Diptera: Tephritidae) on Qualitative Changes of Olive Oil

Citation: Egypt. Acad. J. Biolog. Sci. (A. Entomology) Vol. 10(2)pp: 4956 (2017) Egyptian Academic Journal of Biological Sciences is the official English language journal of the Egyptian Society for Biological Sciences, Department of Entomology, Faculty of Sciences Ain Shams University. Entomology Journal publishes original research papers and reviews from any entomological discipline or from directly allied fields in ecology, behavioral biology, physiology, biochemistry, development, genetics, systematics, morphology, evolution, control of insects, arachnids, and general entomology. www.eajbs.eg.net Provided for non-commercial research and education use. Not for reproduction, distribution or commercial use.


INTRODUCTION
Olives oleaeuropea (L) (oleacea) are one of the main fruit crops in Egypt specially Sinai, Ismailia and Suez governorates.Olive trees are grown on 10 million ha in the world with 96% of production concentrated in the Mediterranean area (Faostat, 2010), where the key pest of olive orchards is Bactrocera oleae (Rossi) (Raspi and Viggiani, 2008), commonly known as the olive fruit fly.The presence of B. oleae, a Tephritidae oligophagous on the fruits of a few Olea species, has long been documented in Mediterranean countries (Daane and Johnson, 2010;Tzanakakis, 2006).Recently, the olive fruit fly was discovered in southern California from where itspread almost throughout the entire state, posing a serious threat to the local olive industry (Daane and Johnson, 2010;Rice et al., 2003).
Nowadays, B. oleae affects almost all the world olive production with few exceptions in isolated areas or where low temperatures limit its occurrence.Olive fruit fly females lay their eggs in fruits of both cultivated and wild olives.Insect development occurs through three larval instars: the hatched larva feeds and grows as a fruit borer in the mesocarp and at the end of the third stage, either pupates in the olive or exit to pupate on the ground (Fletcher, 1987;Tzanakakis, 2003).In the field B. oleae larval development is largely temperature-dependent and the resulting number of annual generations depends on humidity as well as the availability and quality of olive fruits (Burrack and Zalom, 2008;Kounatidis et al., 2008).Oviposition punctures by B. oleae cause a marked depreciation of fruits for table consumption (Tzanakakis, 2006), whereas the detrimental effects on oil production consistmainly in premature fruit drop, larval consumption of fruit pulp (estimated to range from 50 to 150 mg per larva, depending oncultivar) (Neuenschwander and Michelakis, 1978), and oil quality deterioration (Angerosa et al., 1992;Gomez-Caravaca et al., 2008;Tamendjari et al., 2009).The extent of the decrease in oil quality depends on the type of infestation, the percentage of damaged fruits, the fruit developmental stage, and the cultivar (Evangelisti et al., 1994).With regard to the type of infestation, a key role is played by the presence of EH produced by the full grown larvae, which destroy cellular integrity and expose the fruit inner tissues to oxygen (Angerosa et al., 1992;Gomez-Caravaca et al., 2008;Kyriakidis and Dourou, 2002).The resulting acceleration of hydrolytic and oxidative processes determines an increase in free acidity and peroxide value P.V. (Gomez-Caravaca et al., 2008).Current limits of free acidity and peroxide value ( PV) for virgin olive oil (V.O.O. ) are 0.8% oleic acid and 20 mEq O 2 /kg of oil, respectively (EU 1989(EU /2003 modifying the ECC 2568/91; E.U.Off.J. Eur. Communities, 2003), whereas the concentration in phenolicco-mpounds is not taken into account for oil classification, yet the modern concept of oil quality is mainly based on phenolic composition (secoiridoids and lignans in particular), which is closely related to the sensory and health properties of VOO (Servili et al., 2004).Although it is well documented that the phenolic content and oxidative stability decrease in oils obtained from fruits damaged by B. oleae attack (Angerosa et al., 1992;Evangelisti et al., 1994;Gomez-Caravaca et al., 2008;Pereira et al., 2004;Tamendjari et al., 2009).Moreover, in previous studies, the effects of B. oleae damage affect on qualitative characteristics and quantify of oils, on addition to the many sources of sample variability (cultivar, orchard location, cultural practices, processing technology) (Gomez-Caravaca et al., 2008, Tamendjari et al., 2009).For instance, the high variability of samples conclude that phenolic content was not a good indicator of B. oleae effects on oil quality Gomez-Caravaca et al. (2008).
The aim of this study was to assess the effect of different levels of B. oleae damage, expressed as infestation percentage of olive fruits on free acidity as oleic acid, Peroxide value, Rancimat, K232, 270 and Validity.

Plant materials:
Trial was conducted an irrigated olive (Oleaeuropaea L.) (Oleacea) orchard (density of 215 trees/feddan) at the a private farms, at Ismailia Governorate (Cairo-Ismailia roadway, Kilo 96), during 2016 season.Sample fruits were taken in period from first week of May till late week of November 2016 from different experiments.Cultural processes were carried out according to guidelines ministry of agriculture of Egypt.In brief, water was supplied during the summer by submergence irrigation.The orchard floor was free from any grasses during times a year.The trees were 15 years in full production and yielded 22.5 kg per tree.The olive fruit fly pre-imaginable infestation was determined four times from the end of July until November to monitor infestation by sampling dragging 100 fruits from 25 trees.Fruits were harvested at date (23 Nov.) Fruits were taken to the laboratory and sectioned under a stereoscopic microscope to determine the infestation percentage of the B. oleae, healthy and damage fruits were recorded, study the effect infestation percent 5, 15,25,35,45,55,65,80,90, 100% and healthy fruits (control or check) on olive oil quality.

Chemical analysis:
Each treatment (infestation %) consisted of three replicates, each replicate of 8 kg.fruits fresh weight (FW), take 24 kg./ treatment maturation fruits were randomly harvested from trees similar in size and productivity.Oil extraction and analysis was carried out at Food Technology Research Institute (FTRI), Agriculture Research Centre (ARC).To reduce potentially negative effects on oil quality resulting from olive fruit fly infestation, the experiments were carried out under optimal conditions for fruit storage and processing.In all experiments, the oil was obtained from the different fruit samples within 24 h from harvest using an Abencor system, consisting of ahammermill and a centrifugal machine.The fruit samples were washed with tap water, crushed with a hammer crusher and the paste mixed.The mixed paste was centrifuged at 1784 rm for 3 min and the oil separated by decantation in a glass cylinder within 8 min.To avoid any contamination from the water phase below, only the top layer of the oil was collected (150 mL) and stored at 4 O Cin the glass dark until analysis.Free acidity, peroxide value, K 232 nm, K 270 nm and rancimat.Table 1.Show that specific measurements to virgin olive oil.The equipment allowed determining both parameters rapidly (within 8 min) on small samples.An aliquot of oil sample (2.5 and 5.0 mL for free acidity and peroxide value, respectively, K 232 nm, K 270 nm, Rancimat at 110 O   2005) of olive oil.Statistical analysis treatment means were separated by least significant differences at P # 0.05 after analysis of variance using a completely randomized design.Linear regression equations were calculated using (SAS Institute, 2007).

RESULTS AND DISCUSSION
Olives Oleaeuropea (L) (Oleacea) are one of the main fruit crops in Egypt especially Sinai, Ismailia and Suez Governorate, infested with pest of olive orchards is Bactr oceraoleae (Rossi).Bactr oceraoleae affect on quality oil as acidity %, peroxide value, rancimat, K232, 270 and validity.The results illustrate that there are significant differences between infestation %, acidity% (as Oleic acid), peroxide value (meq/Kg oil) and rancimat.The results illustrate that positive correlation between Infestation % + acidity %( r= 0.972), infestation percent + peroxide value (r= 0.940) and acidity % + peroxide value (r= 0.898), but there are negative correlation with other treatments.

Impact of infestation percentage on peroxide value of olive oil.
Data in Fig. 2 Show highly significant differences between infestation percentage and peroxide value.The results reported that peroxide values increase with increasing infestation %, where peroxide value was low to 4.28 meq O 2 / kg.oil in treatment olive fruit free from any infestation compared with olive oil extracted from olive fruits100% damage 4.9 meq O 2 / kg oil.On the other hand, other treatments record 4. 48, 4.5, 4.51, 4.6, 4.64, 4.67, 4.7, 4.8 and 4.85 Meq O 2 / Kg. olive oil in case 5, 15,25,35,45,55,65, 80 and 90% infestation.

Impact of infestation percentage on rancimat and validity on rack of olive oil.
The rancimat is most commonly applied to measure the oxidation stability of vegetable and animal oils and fats , to examine the effectiveness of antioxidants.Data in Fig. 3.and Table 2 indicate that olive fruits free from infestation with Bactrocera oleae give virgin olive oil have 26 month validity on rack and rancimat 13at 110 O C, on the reverse in case of virgin olive oil extracted from olive fruit infested with Bactrocera oleae 100% infestation, record lower validity on rack 17.5 month and rancimat 8.77.These results agreement with Nikolaos, B.K. 2002, founded that Olive oil extracted from olive fruits attack with B. oleae had higher initial values and a higher rate of increase of the parameters measured.The only parameter affecting oil quality was K270.Maximum storage time within legal limit for K270 was 16 days for fly uninfected and 10 days for fly infected olives and Mraicha et al. 2010.Results showed that both attacks by B. oleae and maturity process affected the quantitative and qualitative composition of the oil.These analyses demonstrated that the degree of fly attack was positively correlated with free acidity.The olive fly, Bactrocera oleae (Gmelin) affects on the quantitative and qualitative production of olive oil, (Stefano et al. 2004) 2) illustrate that effect of infestation olive fruit with B olea on K232 and K 270 nm .In case of , K 232, the results show that K 232 value ranged between 0.15 and 0.23 low from 2.6 , while in case of K 270 the values ranged between 1.8 to 2.33 increase than ≤ 0.22 according to E.U.Off.J. Eur.Communities.2003.Simple correlation and regression between infestation percentage and acidity %, peroxide value and rancimat.
The results in Table 3 illustrate relationship simple correlation and polynomial between infestation % and other measurements.There are positive correlation between infestation %, acidity % and peroxide value, also acidity %and peroxide, but there are negative correlation with infestation % with rancimat, acidity with rancimat and peroxide with rancimat record-0.986-0.971and 0.925, respectively.In addition, C and Validity were determined according to A. O. A. C (2005), Hardon and Zurche (1974) and I. O. O. C. (

Table 1 :
Specification measurement standards for Grades of Olive Oil

Table 3 :
Correlation and regression between infestation percentage and acidity % , peroxide value and rancimat.