acidityfood-science
It is commonly known that if your food is too acidic, you lower the acidity of the food by adding something sweet. Is this correct?
Acidity can me measured by pH. Does the sweet actually raise the pH(less acidic) or does the pH stay the same and the sweet only mask the taste of the acidity.
Beer is made from malted cereal grains. These can be corn but more commonly malted barley. The malting process turns the starch in the grain into sugars then the fermentation turns the sugars into beer. To get a strong dry beer, first start with a sweet malt and the ferment until as much sugar as possible becomes alcohol. For a non alcoholic beer, you need to remove the alcohol so you start with a low sugar malt and ferment just long enough to get the flavour but not too much alcohol. Since the fermentation is short, even through the initial sugar content might be low, there is sugar left in the beer thus giving you a sweet taste.
See the improved answer here: What DOES Help?
Which acid works best to keep avocados from browning?
Answer: None (of the acids tested)
It's not that acid doesn't do much to help.
ALL OF THE ACIDS TESTED CAUSED AVOCADOS TO BECOME MORE BROWN AND TO BECOME BROWN FASTER THAN NO TREATMENT AT ALL
I am not kidding.
Method
For acid, I used freshly squeezed lemon juice, freshly squeezed lime juice, distilled white vinegar (diluted to 5% acidity), and Ball brand Fruit Fresh mixed per package instructions, 2 tsp powder to 3 TBS water. Fruit Fresh contains dextrose, ascorbic acid, citric acid and silicon dioxide. According to the label, 1/4 tsp of the powder contains 230% of the US RDA of Vitamin C (ascorbic acid). That roughly translates to the solution I used having 100X the concentration of Vitamin C of lemon juice. I was not able find anything to give me a basis for comparison of citric acid concentration.
I diced 1 avocado and shuffled up the chunks so that no 1 pile had chunks from only 1 part of the fruit. I dropped the chunks into small bowls of the acids, removed the chunks, and allowed to air dry. They remained at room temperature for 24 hours.
I mashed 2 avocados together and put 50 grams of the mash into each of 5 small bowls. I added 1/4 tsp of each individual acid to each bowl, leaving 1 bowl plain. I mixed thoroughly and scooped the mash onto 2 plates, 1 to be refrigerated, and 1 to be left at room temperature. I washed and dried the scoop between changes in acid.
Results
The diced avocados just gradually became darker over 24 hours, with the vinegar treated fruit the first to show signs of browning, and ultimately the vinegar treated fruit became the darkest. The untreated fruit resisted browning the longest and ultimately browned the least. The lemon juice and lime juice were about tied, they both significantly sped darkening and ultimately became significantly darker than the untreated fruit. The Fruit Fresh barely made any difference, but the slight difference there was, was negative. Fruit Fresh also caused the avocado to become darker and to brown faster, but just barely.
At 24 hours all of the mashed, unrefrigerated avocado had become equally brown and unappetizing, it just happened faster to the treated avocado. The difference was most dramatic at 6 hours:
It's not clearly visible in the photo, but the Fruit Fresh treated avocado was ever-so-slightly more brown than the untreated avocado.
At 6 hours none of the refrigerated, mashed avocado was significantly browning.
At 24 hours all of the mashed avocado was the worse for wear. On the non-refrigerated side, it looks on this photo like the vinegar treated avocado ultimately fared the best. It actually didn't. I didn't think to snap a picture, but the vinegar treated avocado was the only one to discolor all the way through. The others were still green on the inside, the vinegar treated scoop was slightly browned even on the inside.
There came a point about 12 hours in that the refrigerated side just stopped browning. It had dried out, leaving it more green than the non-refrigerated side, but no more pleasant. All of the samples browned and dried out fairly equally.
At 48 hours I had one scoop of mashed avocado left that I cared to eat.
By adding nothing, keeping it refrigerated and covered in plastic wrap clinging to the surface, so that it had no air at all, this avocado is still fresh, green and ready to eat.
I'll add lime now for flavor, and some cilantro and cumin. Pass the chips.
Note:
I am honored that this answer has been so generously received, but the fact is, it really doesn't answer the question very well. This answer shows what doesn't help. As of 1/8/15 I have added and accepted a new answer based on new experiments that show what does help, it's HERE next to the checkmark.
Best Answer
Yes, it is incorrect. The correct thing to say is that it reduces sourness. Sourness is a taste, and sweetness indeed reduces it, and vice versa. Coca Cola classic has the same pH as vinegar, 2.5, but the cola is sweet and the vinegar is sour, because the sugar in cola is enough to compensate the acidity and push the taste into the sweet range.
Acidity is a chemical quality of a solution, and is given by the amount of hydrogen ions freely available. It is not changed by the amount of sugar (except for very strong acids like sulfuric acid, which would react with the sugar and bind some protons in the reaction). Acidity "creates" sourness in the sense that we taste acidic food as sour, but as you can see in the sweetness example, our tongues aren't a perfect sensor and can be fooled by the presence of sweet substances, or also other things like miracle berries.
Note that sweetness really reduces sourness, and doesn't just "mask" it the way it masks bitterness or saltiness for some people.