## Core Concept
Fermentation of pulses involves the breakdown of complex nutrients into simpler forms by microorganisms, enhancing nutritional bioavailability. This process affects the content of various nutrients, including proteins, carbohydrates, and minerals. Understanding the impact of fermentation on nutrient content is crucial for evaluating the nutritional benefits of fermented foods.

## Why the Correct Answer is Right
Fermentation of pulses generally increases the bioavailability of nutrients such as proteins, carbohydrates, and some minerals like calcium, iron, and zinc. It also enhances the content of certain B vitamins due to microbial synthesis. However, fermentation can lead to a decrease in the content of certain nutrients, particularly those that are water-soluble or sensitive to microbial activity.

## Why Each Wrong Option is Incorrect
- **Option A:** Fermentation can increase the bioavailability of proteins by breaking down anti-nutritional factors like phytic acid and improving protein digestibility.
- **Option B:** The process can enhance the bioavailability of minerals such as iron, zinc, and calcium, making them more easily absorbed by the body.
- **Option C:** Fermentation increases the content of certain B vitamins, as microbes involved in fermentation can synthesize these vitamins.

## Why Option D is Correct (Implicitly)
- Since the question asks for what fermentation does not increase, and given that fermentation generally enhances the nutritional value of pulses by increasing bioavailability of proteins, certain vitamins, and minerals, the correct answer must relate to a component that either remains unaffected or decreases during fermentation.

## Clinical Pearl / High-Yield Fact
A key point to remember is that fermentation can reduce the content of **phytic acid**, an anti-nutritional factor, thereby increasing mineral bioavailability. However, the question seems to focus on what does not increase, implying a need to consider nutrients that might be lost or remain unaffected during fermentation.

## Correct Answer: D.