What you are describing is a lack of stomach acidity. The bloating and burping is caused from the food putrifying instead of digesting. As the food sits there and ferments carbon dioxide gas is formed causing the bloating and burping. Lack of stomach acid can also contribute to yeast overgrowth that also contributes to the gas formation due to fermentation of sugars in the diet.
As for acid and protein, yes you are right. The protein digestive enzyme pepsin cannot work without sufficient stomach acid. Meats are not the only source of protein. Plants also contain proteins. So a lack of stomach acid can also interfere with the digestion of plant material
Here is a detailed write up on digestion I did previously:
As for digestion, the biggest mistake people make is that they tend to use products that alkalinize the stomach acid. This is a REALLY BAD idea!!! The stomach acid serves various purposes such as preventing dangerous microbes from entering the body through the digestive system, mineral absorption, vitamin absorption, and protein digestion (the protein digestive enzyme pepsin cannot work without sufficient stomach acid). A lot of the problems we see with aging including wrinkles, emphysema, osteoporosis, diverticulitis, hormone imbalances, acid reflux, nutritional deficiencies can all be linked back to declining stomach acid levels as we age. This leads to the loss of nutrients, in particular silica needed for collagen and elastin formation, minerals, and B vitamins. We all know that taking antacids and acid blockers are detrimental to the health for these reasons, but the same applies to alkaline waters, baking soda, oyster shell, coral, dolomite, lime, etc. all of which wipe out the stomach acid. These should NEVER be ingested if someone wants to remain healthy. Not only will neutralizing the stomach acid lead to nutritional deficiencies, but it will also lead to microbial diseases. There is a very persistent myth that pathogenic microbes thrive in an acid environment. The fact is that the majority of pathogenic microbes actually not only live, but thrive in an alkaline environment. Take for example the Helicobacter pylori (H. pylori) bacteria, which causes ulcers and stomach cancer. The reason H. pylori secretes highly alkaline ammonia in the stomach is to neutralize the stomach acid so it can survive. It requires an alkaline environment to survive. And then there is E. coli, which normally inhabits the alkaline intestines. Not everyone who ingests E. coli becomes sick. The elderly and young children are the most prone to E. coli induced illness. Why? Because in both cases there is less stomach acid to kill the bacteria if ingested. And why do antibiotics cause yeast infections, particularly in women? It is because the vaginal canal, like the skin, is supposed to be slightly acidic. The Lactobacillus bacteria that inhabit the skin and vaginal canal produce lactic and acetic acids to control the growth of bacteria and fungi. When the antibiotics kill off the Lactobacillus bacteria the pH shifts to the alkaline side and secondary infections result as the bacteria and fungus are now in a more hospitable alkaline environment rather than a hostile acidic environment. Getting soap in the vaginal canal also causes yeast infections because the highly alkaline soap again shifts the environment to a more bacterial and fungal friendly alkaline environment.
Getting back to digestion, the best ways to improve digestion are:
-Get a little trace element salt in your diet. Stomach acid is formed from salts. For example sodium chloride is split then the sodium becomes sodium bicarbonate. The chlorine atom is combined with hydrogen to form hydrochloric acid, otherwise known as stomach acid.
-Eat foods rich in B vitamins. B vitamins are essential for the formation of stomach acid. It needs to be noted though that the B vitamins needed for stomach acid formation (B6, folate) also require sufficient stomach acid for their absorption,
-Zinc also acts as a catalyst for the formation of stomach acid. Recommended dose is 50mg daily with a large meal. Again, zinc requires sufficient stomach acid for its absorption.
-Taking a little apple cider vinegar or a vitamin C (ascorbic acid) with meals will help with the absorption of these minerals.
-Digestive bitters help to stimulate the release of stomach acid, bile and pancreatic enzymes. They are sold in health food stores, and they must hit the tongue to work. Recommended dose is 1/2 dropper full with meals. Drink plenty of water throughout the day when using bitters since they will also flush the liver out.
-The supplement trimethylglycine (TMG), derived from beet leaves, is a strong methyl donor. It helps in the formation of stomach acid among many other things. There are about 4,000 methylation reactions in the body, so TMG can do a whole lot of good for the body.