Mineral composition of the papaya (Carica papaya variety sunrise) from Tenerife island

In this study we have determined the contents of macroelements (Na, K, Ca, Mg and P) and microelements (Fe, Cu, Zn, Mn and B) in papaya samples (Carica papaya) obtained and consumed on the island of Tenerife, Canary Islands. The analysis shows the existence of significant differences in mineral content in the papaya samples. The papaya coming from MercaTenerife (wholesaler) presents higher K, P and Mn concentration levels than the papaya coming from the South Area of Tenerife. On the other hand, Na concentration levels are higher in the samples coming from the South Area of the island. There are differences between the mineral contents of this fruit shown in some food composition data tables and those analyzed in this work. The former are lower in Na, K, Ca and higher in Fe. In the same way, it is appreciated that the levels of Na concentration found in this work are greater than those found by other authors, and lower in Fe. When we compare the results obtained in this work and the recommended daily intakes or daily estimated demands of mineral elements proposed by different institutions or authors we realize that papaya is an important source of certain mineral elements, mainly K, Mg and B.     

Mineral composition in four varieties of avocado (Persea gratissima, L.) from the island of Tenerife

The contents of macroelements (Na, K, Ca, Mg, and P) and microelements (Fe, Cu, Zn, Mn, and B) of four varieties of avocado obtained and consumed in the island of Tenerife, Canary Islands, have been determined. The samples mineral contents of the different avocado varieties showed significant differences. Thus, the concentration levels of Ca, Mg, and Mn are higher in the Hass variety; those of K, Fe, and Zn, in the Orotava variety; those of Na and B in the Hass and Fuerte varieties; that of P in the Arona and Hass varieties; and that of Cu in the Arona and Fuerte varieties. The area of origin of Hass avocado also influences the mineral content of the samples: those from the north of Tenerife show higher contents of K, Ca, P, Fe, Cu, Zn, and B, and those from the south, of Na, Mg, and Mn.     

Isolation,purification and characterisation of polygalacturonase from ripened banana (Musa acuminata cv. Kadali)

Bananas are the most important fruit crop in the world. Short shelf life of the fruit is the major limiting factor in international trade, and this is due to the softening of the pulp during ripening. Fruit softening is an important aspect of ripening process in fleshy fruits and is caused by the cumulative action of a group of cell wall‐modifying enzymes. Polygalacturonase (PG) is the key enzyme involved in the fruit softening process in banana, and this study reports the isolation, purification and characterisation of polygalacturonase enzyme from ripened fruits of a delayed ripened banana cultivar found specifically in Kerala (Musa acuminata cv. Kadali). PG was purified by ammonium sulphate fractionation followed by DEAE cellulose ion exchange chromatography and gel filtration using Sephadex G 100. The purified protein showed two subunits on SDS‐PAGE and a single band on native PAGE. Enzyme showed maximum activity at pH 3.5 and 40 °C. Fe³⁺ enhanced the activity more, while Mg²⁺ and Ca²⁺ slightly stimulated the activity of purified enzyme. Km value for substrate polygalacturonic acid was 0.06%.     

Combined effect of high pressure,temperature and holding time on polyphenoloxidase and peroxidase activity in banana (Musa acuminata)

Polyphenoloxidase and peroxidase enzyme activities were evaluated following combined pressure, temperature and holding time treatment in banana (Musa acuminata). Using pressures of up to 110 MPa, temperatures of up to 70 °C and holding times of up to 25 min, based on a 2³ central composite design, the interactive effects were found to significantly influence the activity of both enzymes in prepared banana pulp. Temperature and pressure were found to influence the inactivation of polyphenoloxidase separately, while temperature, pressure and holding time were found to influence the loss of peroxidase in the banana, although no significant interactive effects were found. The reduction in polyphenoloxidase activity was found to be less influenced by the combined treatment than peroxidase activity, thought to be due to solubilisation of the enzyme and effects of the soluble solids content. © 2000 Society of Chemical Industry     

Anthocyanins from banana bracts (Musa X paradisiaca) as potential food colorants

Banana (Musa X paradisiaca) bracts, abundant edible residues of banana production, were investigated as a potential source of natural colorant. Anthocyanins were extracted with acidified methanol, purified using C-18 resin, and characterized by UV-visible spectroscopy, physicochemical reactions, HPLC, and electrospray mass spectrometry. Monomeric anthocyanin content was 32.3 mg/100 g bracts on a cyanidin-3-rutinoside basis. Color characteristics (Hunter CIE L*hc) of a solution (absorbance of 0.3, 520 nm, pH 3.5), were L*=86.8, h=44.2 and c=12.7. Cyanidin-3-rutinoside represented ∼80% of the total pigment. Other anthocyanins were 3-rutinoside derivatives of delphinidin, pelargonidin, peonidin and malvidin. One acylated anthocyanin (∼2% of the pigment) was found but not identified. Acid hydrolysis of anthocyanins revealed the concomitant presence of six more common anthocyanidins (delphinidin, cyanidin, petunidin, pelargonidin, peonidin and malvidin) suggesting that, besides being a good pigment source, it could also be a useful tool for anthocyanin identification.     

牛蕉、西贡蕉后熟过程中的品质变化研究

采收七成半成熟度的香蕉进行后熟,比较了牛蕉和西贡蕉在感官特性、理化特性、生化指标和加工特性上的差异,结果表明,牛蕉和西贡蕉都具有高淀粉、高果胶和高糖、高酸的特性,在淀粉、果胶、可溶性固形物、可滴定酸、风味、多酚氧化酶等方面表现出了明显的差异,从而使牛蕉和西贡蕉在香蕉脆片、果汁加工等方面表现出了不同的加工特性。     

Chemical composition of tomato (Lycopersicon esculentum) from Tenerife,the Canary Islands

Chemical composition (moisture, ash, total fibre, protein, glucose and fructose), the taste index and maturity were determined in five tomato cultivars (Dorothy, Boludo, Thomas, Dominique, Dunkan) which were cultivated using intensive, organic and hydroponic methods in Tenerife. The chemical composition was similar to most of the data found in the literature. There were many significant differences in the mean values between the analysed parameters according to the cultivar, cultivation method, region of cultivation and sampling period. Glucose and fructose concentrations were strongly and positively correlated, suggesting the common origin of both sugars. The moisture correlated inversely with the rest of the analysed parameters. Applying a stepwise discriminant analysis (DA), low percentages of correct classifications were obtained according to the cultivar and cultivation methods. The correct classification of the tomato samples improved when the DA was applied to differentiate the tomatoes according to the sampling period.     

Antioxidant capacity and phenolic content of different solvent extracts from banana (Musa paradisiaca) and mustai (Rivea hypocrateriformis)

In the present study, chloroform, acetone, and methanol extracts from stem and flower of banana (Musa paradisiaca) and leaves, stem, and flowers of mustai (Rivea hypocrateriformis) were evaluated for their in vitro antioxidant activity using ferric reducing antioxidant power (FRAP), 2,2-diphenyl-1-picryl-hydrazyl (DPPH^•), 2,2′azinobis (3-ethylbenzothiozoline-6-sulfonic acid) diammonium salt (ABTS^•+), iron chelation, and antihemolytic activity. Among the solvents used, methanol gave the maximum yield in banana, whereas in night glory acetone was reported to having higher extractive value. The total phenolic content was also higher in these extracts. The antioxidant potential of the extracts was well established with their DPPH^• and ABTS^•+ radical scavenging activities and ferric reducing antioxidant capacity. The potential of multiple antioxidant activity of samples can be further evidenced by inhibition of reactive oxygen mediated erythrocyte cell lysis and metal ion chelating activity. However, this is the first report on the antioxidant property of mustai and this plant is having excellent antioxidant potential over banana. In conclusion, the results implied that the leaves, stem, and flowers of banana, and mustai could be considered as health supplements and nutraceuticals/functional foods.     

EFFECT OF PROTEIN SYNTHESIS INHIBITORS ON THE CLIMACTERIC OF BANANA (Musa acuminata)

Protein synthesis inhibitors (Actinomycin D and cycloheximide) were infiltrated into banana slices by contact or under vacuum. Drastic reduction of the climacteric period was observed in both types of infiltration when cycloheximide was infiltrated into slices, compared to the Actinomycin D group and to a control group infiltrated with water. Ethylene production was stimulated when both protein synthesis inhibitors were used, in comparison to the water control group irrespective of the type of infiltration adopted. Ethylene production was higher in the vacuum infiltrated groups. It is suggested that cycloheximide and Actinomycin D affect the equilibrium of ripening differently, giving rise to the distinct responses observed.     

Ultrafiltration of Banana (Musa acuminata) Juice Using Hollow Fibers for Enhanced Shelf Life

Banana juice was clarified by cross flow ultrafiltration using a hollow fiber module under total recycle mode. Three surface-modified polysulfone-based membrane cartridges with molecular weight cut-offs 10, 27, and 44 kDa were used to identify the most suitable membrane. The effects of operating conditions—namely, transmembrane pressure drop and cross flow rate on the permeate flux and permeate quality, have been investigated. The quality of the clarified juice was evaluated in terms of viscosity, clarity, color, alcohol insoluble solids, total soluble sugar, pH, protein, and polyphenol content. The results showed that the membrane of molecular weight cut-off 27 kDa was suitable. The permeate flux depended strongly on the transmembrane pressure drop, but its variation on cross flow rate was insignificant. The clarified juice had high clarity and no pectineous materials (in terms of alcohol insoluble solids). It contained significant amount of polyphenol and protein. The storage study indicated that the juice could be successfully stored for 1 month without any additive and preservative, keeping its natural nutritional qualities, taste, and flavor intact.     

Flour of banana (Musa AAA) peel as a source of antioxidant phenolic compounds

Banana peel is an underused by-product that can be processed to obtain flour that is more easily stored for further uses. The extracts of banana peel flour exhibited a high total phenolic content (around 29 mg/g, as GAE) due to the occurrence of important amounts of flavonoid phenolics: highly polymerized prodelphinidins (around 3952 mg/kg), followed by decreasing lower contents of flavonol glycosides (mainly 3-rutinosides and predominantly quercetin-based structures, accounting for around 129 mg/kg), B-type procyanidin dimers and monomeric flavan-3-ols (jointly around 126 mg/kg). The high total phenolic content of extracts of banana peel flour is likely responsible for the very high antioxidant activity (μM/g, as Trolox equivalents) measured by three different methods: FRAP, around 14 μM/g; ABTS, around 242 μM/g; and ORAC, around 436 μM/g. All these results suggest the interest in going in depth of the good use of banana peel as a profitable source of bioactive phenolic compounds.     

Production of a banana (Musa cavendishii) extract containing no polyphenol oxidase by ultrafiltration

The objective of this research was the production of a banana extract containing no polyphenol oxidase by ultrafiltration. Banana juice was extracted after inhibition of polyphenol oxidase using a solution containing 0.15 g per 100 ml of sodium metabisulphite and 1 g per 100 ml of ascorbic acid in distilled water to avoid initial browning. Polyphenol oxidase was then retained by ultrafiltration using polysulphone membranes with a cut‐off of 20 kDaltons. Two transmembrane pressures, 600 and 800 kPa, were used but 600 kPa was preferred because of the more stable permeate flux which decreased less with time and concentration of extract. © 1999 Society of Chemical Industry     

UPLC法测定香蕉、皇帝蕉皮及其果肉中羽扇豆酮含量

目的:建立超高效液相色谱法分离和测定不同收集期的香蕉和皇帝蕉皮及其果肉中羽扇豆酮含量的方法,并优化提取条件。方法:采用甲醇回流提取法对2种蕉皮及其果肉的羽扇豆酮进行提取分离,减压浓缩,选用Waters ACQUITY UPLC BEH C18色谱柱(2.1 mm×50 mm,1.7μm),流动相为乙腈-水(85∶15,V/V)溶液,流速0.3 mL/min,柱温30℃,检测波长206 nm。结果:香蕉和皇帝蕉果肉中均未检测出羽扇豆酮,但2种蕉皮中有较高含量的羽扇豆酮,并且在16.70~59.96 mg/100 mL质量浓度范围内有良好线性关系(r=0.999 6),羽扇豆酮平均回收率为99.00%,相对标准偏差为3.0%。结论:该法回收率高、重复性好,且具有专属性强、准确性高和简便快捷等特点,适用于香蕉、皇帝蕉皮中羽扇豆酮的含量测定。     

Chemical composition of unripe (green) and ripe plantain (Musa paradisiaca)

The proximate chemical composition, the carbohydrate constituents and the amino acid make-up of green and ripe plantain were determined. The quantity of total sugars considerably increased during ripening from 3.0 to 31.6% in the peel and from 1.3 to 17.3% in the pulp while starch concentration decreased from 50 to 35% and from 83 to 66% in the skin and the pulp, respectively. The skin was richer in cellulose (10%) and hemicellulose (13%) than the pulp which had 1.4% cellulose and 1.3% hemicellulose. The pulp protein was abundantly rich in arginine, aspartic acid and glutamic acid. Methionine was present in the lowest amount with tryptophan and cystine conspicuously being absent.