GB1585607A

GB1585607A - Bananas

Info

Publication number: GB1585607A
Application number: GB3895077A
Authority: GB
Original assignee: Catalytic Generators Inc
Current assignee: Catalytic Generators Inc
Priority date: 1977-09-19
Filing date: 1977-09-19
Publication date: 1981-03-11

Description

(54) IMPROVED BANANAS (71) We, CATALYTIC GENERATORS, INC, a corporation organized and existing under the laws of the State of Virginia, United States of America, of 700 Boundary Avenue, Chesapeake, Virginia 23324, United States of America, do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed to be particularly described in and by the following statement:- The banana is known to posess an underpeel, which is located about 1/16 to 1/8 of an inch below the surface of the exterior skin.

This underpeel contains many of the vessels that contain latex, which is the cause of the darkening when the underpeel attains a temperature in the range 450 to 550F. The precise structure and formation of the latex vessels are not clear but their presence has been clearly determined. Lining these latex vessels are cell membranes which are normally substantially impenetrable by the liquids and solutes normally present in the cells formed by the cell membranes. As long as the cell membranes keep the latex in the latex vessels separate from the liquids and solutes in the cells, there is apparently no interaction that produces the characteristic darkening, which results in a banana incapable of commercial sale. However, the cell membranes undergo a phase change at temperatures of 55"F and below: the lower the temperature, the more rapid and complete the phase change. During the phase change within the cell membranes, it is believed that the liquid-crystalline structure undergoes a transition to a solid-gel phase, which has greater premeability for the liquids and solutes in the cell surrounded by the cell membrane. This greater premeability permits of the inter-mixing of the cell contents into the latex vessels resulting in the darkening of the latex.

The present invention is based on the discovery that an oleaginous material, when applied at temperatures above 55 F followed by an appropriate dwell time, will, upon application to the exterior skin of the banana, penetrate substantially completely down to the sites of the latex vessels and cause a swelling of the cell membranes lining those vessels. The swelling of the cell membranes has been found to change the electron-spin resonance in the cell membranes and decreases the cell membrane permeability to contained phosphate ions. The change in the electron-spin resonance and the decreased cell membrane permeability to contained phosphate ions by reason of the presence of the oleaginous material are detectable and measurable characteristics of the cell membrane. These are achieved solely due to the presence of the oleaginous material. The cell membrane so changed in its characteristics is found to be capable of withstanding tempera tures that would otherwise be considered to be in the chill damaging range.

In accordance with the present invention, there is provided a method of swelling cell membranes of the cells surrounding the latexcontaining vessels in the underpeel of bananas to enable these latex vessels to be more resistant to temperatures within the range 45 F to 55"F, comprising applying to the exterior peel of a banana finger, an oleaginous material while maintaining the temperature of the under peel above 55"F and, after application of the oleaginous material, maintaining the said temperature for a dwell period of at least 24 hours, the amount of oleaginous material being sufficient to permit of its penetrating below the exterior peel and into the sites of the latex vessel cell membranes to swell the said membranes in order to prevent both a phase change in the cell membranes and an increase in the permeability for the liquid and solutes of the cells surrounding the latex vessels into the latex contained in these vessels.

The present invention also provides a banana in which the cell membranes of the cells surrounding the latex-containing vessels in the underpeel contain an oleaginous material in an amount sufficient to produce swelling of the cell membranes, to change the electron-spin resonance of the cell membranes and to lessen the permeability of the cell membranes to ions within the cells, whereby a phase change in the cell membranes is prevented at a temperature in the range 45 to 550F.

The oleaginous materials that are useful in the method of the present invention include the saturated and unsaturated oils that may be broadly classed as mono-, di-, and tri-glycerides.

Typical of the type of oils found useful are oils derived from the soybean, cotton seed, olive, corn, peanut, safflower, linseed, tung and coconut. These and other oils may also be referred to as vegetable oils.

Other oleaginous materials include all types and grades of mineral oil, and dimethyl polysiloxane. The molecular size and chain length of the dimethyl polysiloxane oil are neither critical nor important. The viscosity of the dimethyl polysiloxane should be in a range from 10 centistokes to 10,000 centistokes with a preferred range of 200 to 500 centistokes.

Phospholipids may also be used in the practice of the invention. The term phospholipid includes a number of materials within the broader class of complex lipids. Useful phospholipids are lecithin, cephanlin and sphingomyelin. Phosphatidyl, phasmalogen and their derivatives with choline, ethanolamine serine and inositol may also be used. These phospholipids are generally similar to any oily wax and may have to be mixed with one of the other oleaginous materials if not sufficiently liquid.

A 10% to 50% mixture by weight with mineral oil for example is acceptable. The total amount of the oleaginous material is the combination of both these ingredients.

The oleaginous material may be applied in any manner such as spraying, brushing, dipping, or the like to the exterior skin of each banana finger. The oleaginous material may be in aqueous emulsion or with a suitable aromatic solvent. The oil and water emulsion may be achieved in any well known manner and may include surfactants and emulsifying agents to effect a homogeneous aqueous emulsion.

Among suitable surfactants are sodium lauryl sulfonate and certain other esters of higher fatty acids.

The amount of the oleaginous material that is to be applied to the exterior skin of the banana should be in a range of 0.01 to 1 ml per banana finger. Preferably, the amount may be in the range of 0.1 to 0.5 ml per banana finger. It has been found that the amount that is applied is not critical provided that sufficient amount of the oleaginous material is present to penetrate below the exterior peel and into the sites of the latex vessels cell membranes to achieve the swelling of the membranes.

In order to achieve the proper penetration of the oleaginous material through the exterior skin and down into the underpeel at the sites of the latex vessel cell membranes, the underpeel must be maintained at a temperature above 55"F during the application and thereafter there must be a holding or dwell period of at least 24 hours, preferably at least 3 days and particularly 4 to 7 days. After the appropriate dwell period the exterior skin is found to be substantially free of any applied oleaginous material and does not constitute a coating on top of the exterior skin but rather an impregnation deep into the underpeel of the banana skin.

In a specific example of the present invention Valery variety bananas were treated at 600F with a safflower seed oil by spraying the safflower seed oil onto the exterior skin of the bananas in an amount calculated to be approximately 0.3 ml per banana finger. The bananas were held for 4 days at 60 F, after which they were subjected to temperatures as low as 50 F for 6 hours. Untreated bananas were also subjected to the same temperature for the same length of time and the control bananas were found to have darkened while the treated bananas were free of darkening. The same test was conducted with bananas of differing matur ity with similar results. Similar tests were conducted with immature bananas on the tree in tropical countries and protection was obtained.

The underpeel of the treated bananas was examined and the cell membranes of the latex vessels were found to have swelled, owing to the presence of the safflower seed oil. Little or no indication on the exterior skin of the presence of safflower seed oil was found, indicating that substantially all of the oil had found the sites of the latex vessels cell membranes.

The electron-spin resonance of the cell membranes was found to have changed at chill temperature, owing to the presence of the oleaginous material, and differed from the electron-spin resonance of the untreated bananas at the same chill temperature. Further tests indicated that the permeability of the membranes was lessened with respect to phosphate ions contained in the cells. The treated bananas, in contrast to the control bananas, were found to have no phase change occurring in the cell membrane. It was determined that this was a reason for preventing the liquids and solutes in the cells from intermixing with the latex in the latex vessels and prevented the darkening from occurring in the control bananas.

WHAT WE CLAIM IS: 1. A method of swelling the cell membranes of the cells surrounding the latexcontaining vessels in the underpeel of bananas to enable these latex vessels to be more resistant to temperatures within the range 45 0F to 55"F, comprising applying, to the exterior peel of a banana finger, an oleaginous material while maintaining the temperature of the- underpeel above 55 F and, after application of the oleaginous material, maintaining the same temperature for a dwell period of at least 24 hours, the amount of oleaginous material being sufficient to permit of its penetrating below the exterior peel and into the sites of the latex vessel cell membranes to swell the said membranes in order to prevent both a phase change in the cell membranes and an increase in the permeability for the liquid and solutes of the cells surrounding the: latex vessels into the latex contained in these vessels.

2. A method as claimed in Claim 1, in

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. olive, corn, peanut, safflower, linseed, tung and coconut. These and other oils may also be referred to as vegetable oils. Other oleaginous materials include all types and grades of mineral oil, and dimethyl polysiloxane. The molecular size and chain length of the dimethyl polysiloxane oil are neither critical nor important. The viscosity of the dimethyl polysiloxane should be in a range from 10 centistokes to 10,000 centistokes with a preferred range of 200 to 500 centistokes. Phospholipids may also be used in the practice of the invention. The term phospholipid includes a number of materials within the broader class of complex lipids. Useful phospholipids are lecithin, cephanlin and sphingomyelin. Phosphatidyl, phasmalogen and their derivatives with choline, ethanolamine serine and inositol may also be used. These phospholipids are generally similar to any oily wax and may have to be mixed with one of the other oleaginous materials if not sufficiently liquid. A 10% to 50% mixture by weight with mineral oil for example is acceptable. The total amount of the oleaginous material is the combination of both these ingredients. The oleaginous material may be applied in any manner such as spraying, brushing, dipping, or the like to the exterior skin of each banana finger. The oleaginous material may be in aqueous emulsion or with a suitable aromatic solvent. The oil and water emulsion may be achieved in any well known manner and may include surfactants and emulsifying agents to effect a homogeneous aqueous emulsion. Among suitable surfactants are sodium lauryl sulfonate and certain other esters of higher fatty acids. The amount of the oleaginous material that is to be applied to the exterior skin of the banana should be in a range of 0.01 to 1 ml per banana finger. Preferably, the amount may be in the range of 0.1 to 0.5 ml per banana finger. It has been found that the amount that is applied is not critical provided that sufficient amount of the oleaginous material is present to penetrate below the exterior peel and into the sites of the latex vessels cell membranes to achieve the swelling of the membranes. In order to achieve the proper penetration of the oleaginous material through the exterior skin and down into the underpeel at the sites of the latex vessel cell membranes, the underpeel must be maintained at a temperature above 55"F during the application and thereafter there must be a holding or dwell period of at least 24 hours, preferably at least 3 days and particularly 4 to 7 days. After the appropriate dwell period the exterior skin is found to be substantially free of any applied oleaginous material and does not constitute a coating on top of the exterior skin but rather an impregnation deep into the underpeel of the banana skin. In a specific example of the present invention Valery variety bananas were treated at 600F with a safflower seed oil by spraying the safflower seed oil onto the exterior skin of the bananas in an amount calculated to be approximately 0.3 ml per banana finger. The bananas were held for 4 days at 60 F, after which they were subjected to temperatures as low as 50 F for 6 hours. Untreated bananas were also subjected to the same temperature for the same length of time and the control bananas were found to have darkened while the treated bananas were free of darkening. The same test was conducted with bananas of differing matur ity with similar results. Similar tests were conducted with immature bananas on the tree in tropical countries and protection was obtained. The underpeel of the treated bananas was examined and the cell membranes of the latex vessels were found to have swelled, owing to the presence of the safflower seed oil. Little or no indication on the exterior skin of the presence of safflower seed oil was found, indicating that substantially all of the oil had found the sites of the latex vessels cell membranes. The electron-spin resonance of the cell membranes was found to have changed at chill temperature, owing to the presence of the oleaginous material, and differed from the electron-spin resonance of the untreated bananas at the same chill temperature. Further tests indicated that the permeability of the membranes was lessened with respect to phosphate ions contained in the cells. The treated bananas, in contrast to the control bananas, were found to have no phase change occurring in the cell membrane. It was determined that this was a reason for preventing the liquids and solutes in the cells from intermixing with the latex in the latex vessels and prevented the darkening from occurring in the control bananas. WHAT WE CLAIM IS:

1. A method of swelling the cell membranes of the cells surrounding the latexcontaining vessels in the underpeel of bananas to enable these latex vessels to be more resistant to temperatures within the range 45 0F to 55"F, comprising applying, to the exterior peel of a banana finger, an oleaginous material while maintaining the temperature of the- underpeel above 55 F and, after application of the oleaginous material, maintaining the same temperature for a dwell period of at least 24 hours, the amount of oleaginous material being sufficient to permit of its penetrating below the exterior peel and into the sites of the latex vessel cell membranes to swell the said membranes in order to prevent both a phase change in the cell membranes and an increase in the permeability for the liquid and solutes of the cells surrounding the: latex vessels into the latex contained in these vessels.

2. A method as claimed in Claim 1, in

which the oleaginous material has a viscosity of 10 to 10,000 centistokes.

3. A method as claimed in Claim 1 or 2, in which the amount of said oleaginous material is in the range 0.01 to 1 ml per banana finger.

4. A method as claimed in Claim 3, in which the amount of said oleaginous material is in the range 0.1 to 0.5 ml per banana finger.

5. A method as claimed in any preceding claim, in which the dwell time is at least three days.

6. A method as claimed in Claim 5, in which the dwell time is from 4 to 7 days.

7. A method as claimed in any preceding claim, in which the electron-spin resonance in the cell membranes is changed and the permeability of the cell membrane to phosphate ions is decreased.

8. A method as claimed in any preceding claim, in which the oleaginous material is a vegetable oil, a dimethyl polysiloxane, a mineral oil, a (mono, di or tri)-glyceride or a phospholipid.

9. A banana in which the cell membranes of the cells surrounding the latex-containing vessels in the underpeel contain an oleaginous material in an amount sufficient to produce swelling of the cell membranes to change the electron-spin resonance of the cell membranes and to lessen the permeability of the cell membranes to ions within the cells whereby a phase change in the cell membranes is prevented at a temperature in the range 45 to 550F.

10. A banana as claimed in Claim 9, in which the amount of the oleaginous material is in the range 0.1 to 0.5 ml per banana finger.

11. A banana as claimed in Claim 9 or 10, in which the oleaginous material is substantially completely in the underpeel of the banana and at least 1/16 inch below the exterior peel skin.

12. A banana as claimed in any one of Claims 9 to 11, in which the oleaginous material is a vegetable oil, a dimethyl polysiloxane, a mineral oil, a (mono, di or tri)-glyceride or a phospholipid.

13. A banana as claimed in Claim 9 substantially as hereinbefore described.

14. A banana treated by a method as claimed in any one of Claims 1 to 8.