Assessment of green solvents and extraction methods

1 Department of Chemistry, College of Arts and Sciences, Central Luzon State University, Science City of 7 Muñoz, Nueva Ecija 3120 Philippines; 8 2 School of Chemical, Biological and Materials Engineering and Sciences, Mapua University, Intramuros, 9 Manila, Philippines; kadecastro@mapua.edu.com 10 3 Department of Crop Protection, College of Agriculture, Central Luzon State University, Science City of 11 Muñoz, Nueva Ecija 3120 Philippines; leafiegalan@gmail.com 12 * Correspondence: danilaparagas1010@clsu.edu.ph; Tel.: +63-044-940-7264 13


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The fruit fly species Bactrocera dorsalis (Hendel) (Diptera: Tephritidae) has been throughout one 32 of the most serious economic pests affecting agricultural fruits in India, East Asia, and the Pacific [1].

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These oriental fruit flies deposit their eggs into fruit and vegetables, and subsequently the flesh are 34 consumed by developing larvae [2]. The fruit flies' invasive action has caused major economic losses 35 in horticultural crops production, and over 90 plants were found out to be affected [3]. Mango, 36 banana, papaya, citrus, and guava are among the country's most important commercial crops 37 attacked. As these fruits are of valuable importance in both domestic and international markets, 38 control and management of this pest is necessary to prevent significant losses in fruit production.

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blender and stored in a tightly covered container until further use.

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Four different methods of extractions were done. These are Soxhlet or hot continuous 98 extraction, hot infusion, fermentation and maceration. Soxhlet method was done as follows: the 99 ground plant material (15 g) was loaded into the cellulose thimble which was then placed inside the 100 Soxhlet extractor. The solvent was heated using the heating mantle and the solvent began to 101 evaporate, moving through the apparatus to the condenser. The condensate then dripped into the 102 reservoir containing the thimble. When the level of solvent reached the siphon it poured back into 103 the flask and the cycle begins again. The process runs for a total of 8 hours.

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Hot infusion was done by adding 15 g of previously weighed ground leaves into 150 mL boiling 105 solvent. The mixture was set aside for 15 minutes. The extract was then filtered using Whatman

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No. 42 filter paper and the filtrate was placed in amber bottle and stored in the refrigerator until used 107 for analysis.

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Fermentation method was carried out by soaking 15 g of the plant material into 150 mL of the 109 solvent. The container was covered with aluminum foil and stored inside the locker. The mixture 110 was set aside for ten days. After which the mixture was then filtered and the filtrate was placed in 111 amber bottle and stored in the refrigerator until used for analysis.

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Maceration was done by placing 15 g of the plant material in 150 mL of the solvent. The mixture 113 was then set aside for one hour, then filtered and the filtrate was placed in amber bottle and stored 114 in the refrigerator until used for analysis.

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Four green solvents were used in this experiment. These are rice wine, rice wash, vinegar, and 117 distilled water. The rice wine was produced at Panupdupan, Lamut, Ifugao, Philippines. The rice 118 wash was prepared by washing 100 g of bungkitan glutinous rice with 100 mL of distilled water. The 119 rice washing was then drained into a beaker. Another 100 mL of distilled water was added to the 120 glutinous rice, washed and the second washing was then added to the first washing. The combined 121 rice wash was then filtered to remove the suspended solids. The vinegar, called sukang "basi" was 122 prepared by fermentation of sugar cane. The other solvent was distilled water.

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In contrast to rice wine, vinegar which also has undergone fermentation and might contain some 176 volatile compounds that attract fruit flies, was able to register the highest mortality. Vinegar significant differences at 5% level (Table 1)

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This shows that neem extracts prepared by fermentation using rice wash and Soxhlet extraction using