State Of Knowledge Report Template For SoK Of WP2: Boiled Plantain Douala, December 2018 Gérard NGOH NEWILAH, CARBAP, Douala, Cameroon Cédric KENDINE VEPOWO, CARBAP, Douala, Cameroon Agnès ROLLAND-SABATÉ, INRA, Avignon, France 0 This report has been written in the framework of RTBfoods project. To be cited as: Gérard NGOH NEWILAH, Cédric KENDINE VEPOWO, Agnès ROLLAND-SABATÉ. 2018. Template For SoK Of WP2: Boiled Plantain. Douala (Cameroon). RTBfoods Project Report, 14p. Image cover page © Dufour D. for RTBfoods. 1 CONTENTS Table of Contents 1 Composition and structure of raw material ........................................................................ 4 1.1 Composition ................................................................................................................ 4 1.2 Structure ..................................................................................................................... 8 2 Processing condition ......................................................................................................... 8 3 Sensory analysis and consumer preference ..................................................................... 8 4 Product characterization and relationship with sensory evaluation ................................... 9 4.1 Evolution of composition and structure with processing ............................................. 9 4.2 Instrumental Texture assessment and relationship with sensory evaluation............... 9 4.3 Relationship between composition and sensory evaluation ...................................... 10 5 Conclusion ....................................................................................................................... 10 6 References ...................................................................................................................... 11 2 ABSTRACT This literature review considers 34 articles and documents investigating banana and plantain postharvest qualities including composition of raw material, processing conditions, sensory analysis and consumer preferences. All these topics were not closely related to boiled plantain, they mostly concerned cooking banana chips and flours obtained from various Musa cultivars. It will be important to carry out more research on boiled plantain characterization related to sensory analysis and consumer preferences. 3 1 COMPOSITION AND STRUCTURE OF RAW MATERIAL 1.1 Composition Physicochemical properties The dry matter content (DMC) of pulp and peel was determined by oven-drying at 105°C for 24 h. Pulp firmness was measured at the centre of the transversal section of the finger, using a manual penetrometer (Cosse model). The pH of the peel and pulp was measured with a digital pH-meter (Inolab, pH level 2), using 15 g pulp or peel blended in 45 ml distilled water. The total soluble solids (TSS) and total titratable acidity (TTA) of the blended pulp were determined using a REF 113 Brix 0– 32 ATC refractometer (Index Instruments, Ramsey, United Kingdom) and a 0.1 N sodium hydroxide solution during titration until the indicator just changes pink/red (Dadzie and Orchard, 1997). The peel thickness, fruit grade and fruit length were determined by measuring the middle fruit in the outer whorl of the second hand with a pair of callipers (Stanley model) and a tape, respectively. The peel and pulp colours were determined using colour charts (IPGRI, 1996). Table 1. Physicochemical properties of bananas and plantains at harvest (Ngoh Newilah et al., 2009, Ngoh Newilah et al., 2011). NGA Fg (cm) Fl (cm) Pt (mm) Peel pH Pulp pH Pulp Peel Pf TSS TTA Musa type DMC DMC Cooking 06 4.0 – 6.0 16 – 28 2.9 – 3.6 5.65 – 5.88– 32–40 9.89– 2.41-3.17 1.2–2.3 270–450 bananas 6.21 6.34 14.5 Dessert 09 2.6 – 4.2 12 – 21 2.1 – 3.3 5.38 – 5.42– 20.5–30 8.63– 1.99 – 3.2 1.2–2.08 405–530 bananas 5.94 5.67 11.5 04 3.0 – 4.5 16 – 25 2.5 – 4.0 5.36 – 5.69– 31 – 34.5 7 – 11 2.15 – 1.10 – 348 – Plantain hybrids 5.86 6.15 3.45 2.80 509 Plantain 11 3.6 – 6.0 22 – 44 3.0 – 4.2 5.50 – 5.80- 34 – 39 9 – 14 2.5 – 3.5 1.20 – 317 – cultivars 5.70 6.20 2.10 436 NGA: number of genotypes analysed; Fg: Fruit girth; Fl: Fruit length; Pt: Peel thickness, DMC: dry matter content (g/100g FW); Pf: pulp firmness (kg/cm²); TSS: total soluble solids; TTA: total titratable acidity Polyphenol contents Banana pulp and peel contains various phenolic compounds, such as gallic acid, catechin, epicatechin, tannins and anthocyanins. Banana contains high amounts of total phenolic compounds and flavonols. The total content of phenolic acids in bananas has been reported to be 7 mg/100 g fresh weight (FW). These compounds impart astringent taste to the unripe banana. Free phenolic compounds (solvent extractable) in the banana pulp ranges from 11.8 to 90.4 mg of GAE (gallic acid equivalent)/100 g FW (Singh et al., 2016). Total polyphenol compounds of dried pulverized Musa pulp were determined at 760 nm using an optimized Folin-Ciocalteu method (Singleton and Rossi, 1965). Table 2. Total polyphenol contents (μg gallic acid equivalents / 100 g dry matter) of bananas and plantains during ripening (Ngoh Newilah et al., 2010). Maturation stage Musa types Number of genotypes Unripe Ripe Fully ripe analysed Plantain hybrids 05 54 – 91 124 – 314 155 – 361 Plantain cultivars 12 27 – 139 32 – 306 105 – 541 Cooking banana cultivars 05 46 – 100 100 – 448 126 – 379 Dessert banana cultivars 10 47 – 104 121 – 415 62 – 465 There are significant levels of total phenolic contents in the pulp of banana (Table 2) and the distribution of phenolic compounds in bananas is affected by maturity and cultivar. The highest total phenolic content in the pulp is for cavendish with 232mg/100g dry matter (DM) and a new banana triploid hybrid (FLHORBAN 920 cultivar, AAA group), partially resistant to Yellow Sigatoka and Black Leaf Streak diseases (334 mg/100g FW) (Singh et al., 2016; Bugaud et al., 2009). Many free phenolic compounds have been identified in ripe banana pulp: gallic acid, catechin, gallocatechin, naringenin-7-0- 4 hesperoside (Verde-Mendez et al., 2003). Several studies have also suggested that consumption of unripe bananas confers beneficial effects for human health, as they might be an important source of phenolic compounds. Unripe dessert banana (Musa cavendish L.) contains dopamine and norepinephrine in high levels (0.72-6.1 and 0.62-1.5 mg/100g FW of pulp) (Kanazawa and Sakakibara, 2000). Hydroxycinnamic acids, particularly ferulic acid-hexoside with 4.4–85.1 µg/g of DM, dominated in the plantain pulp and showed a large diversity among cultivars (Passo-Tsamo, et al., 2015a). Carotenoid contents 1. Unripe, starting to ripe, ripe and fully ripe fruits of Musa cultivars sourced from the CARBAP collection in Cameroon were analyzed for their total carotenoid levels by UV-VIS spectrophotometry at 450 nm. Three inner fruits of 104 cultivars from the first, median and last hands were cut longitudinally and compared to two colour fans; one based on the flesh colour variation in potato, developed on the initiative of the CGIAR HarvestPlus Challenge Programme, and the other based on egg yolk colour variation developed by DSM. Table 3. Pre-screening Musa cultivars for proVitamin A using colour charts (Ngoh Newilah et al., 2008) Musa types Number of genotypes Harvest Plus colour fan DSM yolk colour fan TCC (µg/g FM) analysed RHS 9/2 - 1355U 9 Plantains (AAB) 08 5 – 26 RHS 9/3 - 7507U 7 Cooking bananas (AA, AAB, RHS 9/2 - 1355U 9 03 3 – 21 ABB) RHS 9/3 - 7507U 7 RHS 5/3 - 7401U 3 Dessert bananas AAA, AAB, AA 03 2 – 3 RHS 3/3 - 1205U 1 Plantain hybrids (AAAB) 02 RHS 9/3 - 7507U 7 ND RHS 9 - 137U 13 PNG cultivars (AA, AAA) 03 9 - 49 RHS 9/3 - 7507U 7 TCC: total carotenoid content; FM: fresh matter; PNG: Papua New Guinea; ND: not determined 2. The quartered and lyophilised pulps of three (03) Musa types were submitted to HPLC techniques for total carotenoid levels determination during postharvest maturation, as well as some specific carotenoids (α-carotene, β-carotene and lutein). Carotenoid extraction was adapted from the method of Rodriguez-Amaya and Kimura (2004) and their analysis were realized according to a published method (Dhuique-Mayer et al., 2005). Table 4. Total carotenoid contents (μg β-carotene equivalent per 100g on fresh matter basis) of three Musa types during ripening (Ngoh Newilah et al., 2010a). Maturation stages Musa types Unripe Start ripe Ripe Fully ripe Over ripe French sombre (plantain) 1631 2543 2355 2341 2485 Pelipita (cooking banana) 1047 1421 1315 1162 1456 Grande naine (dessert banana) 182 185 225 250 355 5 Table 5. Specific carotenoid contents of Musa pulps during ripening in Cameroon (μgꞏ100 g–1 dry matter) (Ngoh Newilah et al., 2009a). Carotenoids Maturation stages Musa types NGA Unripe Ripe Fully ripe α-carotene 2100 – 4200 1450 – 3200 450 – 2100 Plantains β-carotene 1700 – 3300 1200 – 2850 330 – 1450 10 Lutein 40 – 190 20 – 190 60 – 325 α-carotene 125 – 1350 125 – 650 165 – 630 Cooking β-carotene 340 – 1120 340 – 590 390 – 680 bananas 03 Lutein < 30 80 – 130 35 – 260 α-carotene 60 – 520 105 – 600 40 – 550 Dessert bananas β-carotene 13 – 370 60 – 250 30 – 215 03 Lutein 50 – 200 60 – 185 80 – 150 α-carotene 1600 – 2100 1700 – 2350 1700 – 3000 Plantains hybrids β-carotene 700 – 1400 950 – 1280 900 – 1600 03 Lutein 20 – 130 20 – 350 10 – 400 NGA: Number of genotypes analysed Other micronutrient contents Carotenoids Analysis. The pVACs contents of aliquots of the filtered, combined extracts were analyzed by RP-HPLC according to the method given in ref 17. Total carotenoids contents were analyzed in duplicate by microtiter plate spectrophotometry at 450 nm, using a quartz microtiter plate (Davey et al., 2006)). In both cases, concentrations were calculated by the external standards techniques using standard curves of freshly prepared 0.1-10 µg/mL all-trans--carotene (t-BC) (Sigma- Aldrich), in extraction solvent (Davey et al., 2006; Schierle et al., 2004). Analysis of Mineral Micronutrient Contents. Aliquots of lyophilized plant tissue powder were digested with 1 mL of high-purity 60-70% nitric acid overnight at room temperature.