I used a juicer to juice vegetables. Then, I used the juice in making bread. Some of my friends said that something in vegetables affects the fermentation, namely the enzymes. They said it can kill the yeast. Is it true? Can you briefly explain?
This is the same user who asked if vegetable juices could stop bread from rising. Dude...yes. I'll try to break this down again...There's probably a combination of things happening: your veggie slurry pH is not condusive for yeast function, the enzymes in the vegetable matrix are being unleashed and working(because you juiced them, and exposed them to light and heat)--thereby producing chemicals that are toxic to the yeast, and lastly if that wasn't stopping the yeast...the beans may be so dense that the yeast organisms can't make bubbles that stay in your dough. Try using a brominated bread flour, letting the bread rise, then fold in fat shredded veg pieces. Pretend you're kind of making a zucchini bread. If you are really bent on success with this, it seems that more if the vegetable cell walls need to be intact once it comes in contact with the dough(inact cell walls = less enzyme activity/bioactive compound release, and maybe even pH buffer Bonus!). I cited at least 4 NCBI articles stating why the above reasons may be occuring. I can provide more reading material to supplement if those were not sufficient.
I am still a bit confused as to why you chose the green vegetables + other legumes you did, and treated them in that manner for use in bread. Like, really confused. I can't comment yet, but if I could...I would, if nothing else than to tailor my response to you. If nutrient-density was the goal, why remove the fiber, and place the bioactive compounds in jeapordy? I do hope that point is clear, your processing choice for the vegetables will be compromising their nutritional impact/effectiveness.
Many of the molecular components that make those vegetables useful for human health degrade in the presence of heat, pH, light, and exposure to air (degraded bioactive molecules are not realy physiologically useful, and just excreted...so what's the point?). You expose those awesome vegetables to extremes in all of those cases. I would be curious to know(if you could get this to work) if there were any biologically relevant compounds left in the finished product...aside from the general macronutrients(carbs, fat,protein, fiber, etc ...they are biologically relevant too, just not what the focus seems to be for this application)
Remember, when vegetables/fruit/whatever are consumed without being overprocessed, the food matrix(even chewed up) provides a barrier from your stomach acid and other endougenous enzymes, and helps naturally preserve some of nutrients until they get to the intestines (where they are actually absorbed). Take away the matrix, your super-charged molecules lose their nutritionally active shape more easily, before they can even be utilized by your body. The remaining food matrix has important funtions health functions too, which I won't elaborate on here. Again, I am happy to provide peer-reviewed sources for this info, should you be interested (but if the other post tells me anything...it is that you possibly don't care). Look yourself anyway, go be curious. Try a pubmed search for bioavailability and the author Gibson to start, the review articles he writes are rather approachable. I would like to mention that there are some processing and pairing techinques can enhance the bioavailibility and bioefficacy of certain nutrients(meat factor & non-heme iron sources, limited thermal proccessing on hard veggies like carrots) and that the extent of nutrient degradation can vary greatly depending on the type of processing(boiling vs microwave vs oven vs freezing vs low-temp vs fermentation...etc).