Hi, I am working on a project and having trouble in color and shelf stability of yam filling. I use 23% fresh yam and 23% of water also, with modified starch, 17% of sugar, potassium sorbate and sodium benzoate as preservative; and artificial violet color. Anyone here can help me on color improvement and shelf life extension? Target color is light purple and target shelf life is 6 months under ambient condition. Do you know what process should I follow? Big thanks! 
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How do you apply the colorant ? Can you give us some details ? If possible photos will be good.
Shelf life point is very sensitive.
For a stable shelf life,
Raw materials quality,
Production techniques, ( Using raw materials or cooked / roasted materials )
Production conditions ( hygiene etc. )
Preservatives and their amounts
Water content and aw
Packaging techniques and pack materials,
Other ingredients those can effect shelf life
are very important.
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For color improvement, there are various options that you could work with and optimize towards your needs. Basically purple carrot powder, blueberry powder, prune juice powder. With regard and color-flavor-taste optimization might be needed in this process.
Heating will further influence (heat degradability of the colors need a separate study as well).
Replacing the modified starch partially with a nonstarch gum + further working on preservatives might improve and have a higher impact on this product.
Will be glad to know more of your solutioning methods that was followed in the coming months. Great work and good luck.
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Hi
First of all I think YAM will be used as a mash. YAM must be boiled first. If possible, it can be heated to 90 cm in a closed container and boiled in hot water or steam. Yam can only be stabilized in this way. As a preservative, you can use alphatocoperole instead of sodium benzoate and potassium sorbate at a rate of 3 per thousand. If you want, you can use sodium benzoate and alfatecoperol together. Due to the smell of potassium sorbate, the product you made may create proplem in taste. The formula you will make in your formula as Yam, Starch sugar, Alfatokoperpl and Glycerol instead of water provides you a shelf life of 9 to 12 months. The packaging you will use must also be completely sealed. If you want to get more information. +90 532 773 31 80 I can help via Watsapp. Good luck with.
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Hi Sir, kindly check my process. Would love to hear corrections and recommendations from you.
The Raw materials I used is of high-quality.
The potassium sorbate I used is 0.3% of the total formulation. Will remove the sodium benzoate, I have read some references that in the presence of Vitamin C and heat, it will decompose to carbon dioxide and benzene (it is quite toxic and confirmed to be a carcinogenic).
The water content is 35% of the total formualtion while the company I am currently working with is technically not yet capable of checking the water activity.
I also added Citric acid as acidulant contributing 0.18% on the formulation.
Big thanks Sir 
Hi Sir/ Ma’am,
Really appreciate your recommendations, but the project I am working with have a very low target price so it limits me from using natural colorants. Also, I combined modified starch and carrageenan as thickening agent and to further hold the water. I think the flowability of my output is fair enough with the price. Please let me know more of your suggestions.
Lots of thanks!
Hi Sir,
Thank you very much for helping, I love your idea of shelf-life extension but as much as I want to follow your suggested combination (Vit E & Glycerol) it will lead to a very high cost implication, my target price for a 500 g Purple Yam Filling is 0.69USD only. I really hold on to the water to simply reduce the cost while increasing the product volume. If you also have an idea of what are the temperature and time parameter for water retorting of pillow pouches, would love to hear from you. Thanks and take care
Hello Rosalyn
In the formula you have applied, you can create a product with a suitable price and long shelf life with the materials you have. First of all, you should use the skimmed milk powder and milk skim. Or you can use whey powder if you want to replace them with a more suitable and nutritious value. The oil in the milk tozoa and thick milk you use prevents the water activity from decreasing by forming a bond with the starch. Also, when mixing these products, the temperature should not exceed 50 centigrade degrees. If you are already using sodium benzoate and potassium sorbate, it is wrong to sterilize this product for 60 minutes at 100 centigrade. This will cause deformation of your product.
Since the temperature of the product you have filled in hot will be pre-sterilized, it is enough to pasteurize it at 90 degrees until the core temperature is 75. For color stabilization, yam should be subjected to pre-boiled or heated. Please send me a picture of a finished trial to [email protected] and I can help you more.
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