The brahmanas from these places (Kanyakubja, Sarasvata, Gauda, Maithila, Andhra, Karnataka, Gujarat, Dravida and Maharashtra) are considered to be very strict followers of the Vedic principles, and they are accepted as pure brahmanas

Expressions researched:
"The brāhmaṇas from these places are considered to be very strict followers of the Vedic principles, and they are accepted as pure brāhmaṇas"

Sri Caitanya-caritamrta

CC Madhya-lila

In northern India the places are Kānyakubja, Sārasvata, Gauḍa, Maithila and Utkala. In southern India the places are Andhra, Karnataka, Gujarat, Drāviḍa and Maharashtra. The brāhmaṇas from these places are considered to be very strict followers of the Vedic principles, and they are accepted as pure brāhmaṇas. They strictly observe Vedic principles and are not polluted by tantric misdeeds. All of these brāhmaṇas respectfully invited Caitanya Mahāprabhu for lunch.

CC Madhya 18.134, Translation and Purport

In the morning they would come to Akrūra-tīrtha and cook food. After offering it to the śālagrāma-śilā, they offered it to Śrī Caitanya Mahāprabhu.

There are brāhmaṇas known as pañca-gauḍa-brāhmaṇas, who come from five places in northern India, and there are brāhmaṇas known as pañca-dākṣiṇātya-brāhmaṇas, who come from five places in southern India. In northern India the places are Kānyakubja, Sārasvata, Gauḍa, Maithila and Utkala. In southern India the places are Andhra, Karnataka, Gujarat, Drāviḍa and Maharashtra. The brāhmaṇas from these places are considered to be very strict followers of the Vedic principles, and they are accepted as pure brāhmaṇas. They strictly observe Vedic principles and are not polluted by tantric misdeeds. All of these brāhmaṇas respectfully invited Caitanya Mahāprabhu for lunch.