Read the text and answer the questions.

    There is a tropical tree named tamarind that is widely spread in several regions around the world. It produces a paste-like, sweet-sour fruit. The young fruit has a green and sour pulp. As it ripens, the pulp becomes more sweet-sour and turns paste-like.

    In the Middle East, South East Asia, Mexico, South Asia, and the Caribbean, people use tamarind pulp to cook. The leaves and seeds of tamarind are edible, too. They can be used in sauces, desserts, chutneys, marinades and drinks. Tamarind pulp also becomes one of the ingredients of Worcestershire sauce.

    In traditional medicine, tamarind has an important role. It was commonly used to cure constipation, fever, diarrhea, and peptic ulcers. Its leaves and bark were also used to treat wounds. The polyphenols in tamarind have anti-inflammatory and antioxidant properties. These can protect against diseases, such as diabetes, cancer, and heart diseases. The pulp extract is able to help you lose weight and reverse fatty liver disease and the seed extract is able to help you lower blood sugar.

41 . When do the fruit become sweet-sour?