Optimum Parameters for Extracting Three Kinds of Carotenoids from Pepper Leaves by Response Surface Methodology

Abstract

To determine the optimum parameters for extracting three carotenoids including zeaxanthin, lutein epoxide, and violaxanthin from pepper leaves by response surface methodology (RSM), a solvent of acetone and ethyl acetate (1:2) was used to extract carotenoids with four independent factors: ultrasound time (20–60 min); ratio of sample to solvent (1:12–1:4); saponification time (10–50 min); and concentration of saponification solution (KOH–methanol) (10–30%). A second-order polynomial model produced a satisfactory fitting of the experimental data with regard to zeaxanthin (R2 = 75.95%, p < 0.0197), lutein epoxide (R2 = 90.24%, p < 0.0001), and violaxanthin (R2 = 73.84%, p < 0.0809) content. The optimum joint extraction conditions of zeaxanthin, lutein epoxide, and violaxanthin were 40 min, 1:8, 32 min, and 20%, respectively. The optimal predicted contents for zeaxanthin (0.823022 µg/g DW), lutein epoxide (4.03684 µg/g dry; DW—dry weight), and violaxanthin (16.1972 µg/g DW) in extraction had little difference with the actual experimental values obtained under the optimum extraction conditions for each response: zeaxanthin (0.8118 µg/g DW), lutein epoxide (3.9497 µg/g DW), and violaxanthin (16.1590 µg/g DW), which provides a theoretical basis and method for cultivating new varieties at low temperatures and weak light resistance.

Genetic Regulation, Environmental Cues, and Extraction Methods for Higher Yield of Secondary Metabolites in Capsicum

“…Ultrasonication of methanolic extracts for about 12 h with a 1:8 sample-to-solvent ratio enabled simultaneous extraction of more than 90.60% flavonoids such as vitexin, isoquercetin, kaempferol-3-glucoside, and myricetin and capsaicin as detected by ultrahigh performance liquid chromatography (UHPLC) . Acetone and ethyl acetate in the ratio 1:2 could extract a highest value of 0.8118 μg g –1 DW zeaxanthin, 3.9497 μg g –1 DW of lutein epoxide, and 16.1590 μg g –1 DW of violaxanthin from pepper leaves, respectively, provided 40 min of ultrasonication, 1:8 sample-to-solvent ratio, and 32 min of saponification with 20% KOH in methanol . Similarly, higher amounts of capsaicinoids and carotenoids were extracted from pepper paste via UAE in refined olive oil at 60 °C and 60% amplitude in less time than maceration, indicating higher extractability of capsaicinoids in vegetable oils .…”

“…223 Acetone and ethyl acetate in the ratio 1:2 could extract a highest value of 0.8118 μg g −1 DW zeaxanthin, 3.9497 μg g −1 DW of lutein epoxide, and 16.1590 μg g −1 DW of violaxanthin from pepper leaves, respectively, provided 40 min of ultrasonication, 1:8 sample-to-solvent ratio, and 32 min of saponification with 20% KOH in methanol. 224 Similarly, higher amounts of capsaicinoids and carotenoids were extracted from pepper paste via UAE in refined olive oil at 60 °C and 60% amplitude in less time than maceration, indicating higher extractability of capsaicinoids in vegetable oils. 225 However, two cycles of accelerated solvent extraction operated at 78 °C for 28 min yielded Capsicum oleoresins with higher total carotenoids (847 ASTA color value) and SHU (57,200 ± 362) as compared to maceration and UAE.…”

Response Surface Methodology to Optimize the Extraction of Carotenoids from Horticultural By-Products—A Systematic Review

“…Table 4 shows the number of levels per factor in each study, and it is essential to highlight that almost 30% of the studies in which CCD was selected as RSM design indicated three levels of each factor. It is necessary to note that three of these studies indicated three levels (−1, 0, +1) in the text, but in the tables of the combinations, five levels were detailed [22,32,45]. In addition, information related to the number of axial points was also included in some studies in which CCD was used.…”

“…Another study indicated in their Data Availability Statement, "Data is contained within the article", but no data was included in the manuscript. Therefore, this manuscript was not included as an affirmative response to Q10 [32].…”

Ultrasound-Assisted Extraction of Natural Pigments From Food Processing By-Products: A Review

“…UAE has been used to extract carotenoids from different fruits and vegetables by-products such as acerola, guava, genipap and umbu seeds and peels ( 72 ), carrot pomace ( 73 , 81 ), cantaloupe peel ( 82 ), mandarin peel ( 54 , 83 , 84 ), Gac fruit peel ( 63 ), mango peel and paste ( 85 ), peel of different varieties of orange ( 38 , 43 , 48 ), orange pomace ( 86 ), pepper leaves ( 87 ), pomegranate peel ( 55 ), pumpkin peel ( 88 , 89 ), purple passion fruit peel ( 90 ), sea buckthorn pomace ( 49 , 91 , 92 ), tomato peel and seeds ( 31 , 93 – 95 ), and arthropods by-product such as shrimp shell and cephalothorax ( 40 , 96 – 98 ). According to these studies, carotenoids can be used as a natural pigment directly in the preparation of various food products such as butter, salad dressing, beverages, ice cream, desserts, candy, bakery, edible oils, meet products, cosmetics, pharmaceutical products, also as an ingredient in feed for aquatic animals and pets.…”