Alternatives to acetylene gas in mango production

Dear list members,
Colleagues of mine in Senegal, West Africa, were recently contacted by a 
women's mango growing cooperative which is looking for alternatives to 
the acetylene gas they spray on mangoes to make them ripen quicker. The 
women have long recognized the effects this gas has on their health--many 
of them get headaches and nausea after applying it--but feel that not 
spraying would mean economic ruin for them and their community. The 
mangoes in their groves all ripen at the same time during the year and the 
women are consequently unable to receive good prices at markets that are 
saturated with the fruit. Spraying the acetylene allows them to sell 
mangoes throughout the year at decent prices. 

However the women are determined to find an alternative to the gas for the 
health of themselves, their children and people who buy the mangoes. They 
are considering multiple options and are looking for either:
1. A substitute for the gas;
2. Ways to pick the mangoes and preserve them until they ripen naturally; 
3. Techniques for processing the mangoes into value-added products like 
juices or jams.

I would appreciate any information on sustainable and economically viable 
mango production that I can pass along to my colleagues in Senegal. Thanks 
in advance for any help you can provide.