IPA: /ˌʌnəˌdʌltəˈreɪtɪdli/
KK: /ʌnəˌdʌltəˈreɪtɪdli/
In a pure or untainted manner, without any mixture or alteration.
The juice was served unadulteratedly, preserving its natural flavor.
Unadulteratedly → It is formed from "un-" (meaning not), "adulterare" (meaning to corrupt or make impure), and "-ly" (meaning in a manner). The word means in a manner that is not corrupted or impure.
Think of 'not' ('un-') corrupting ('adulterare') something — that's why unadulteratedly means in a pure or genuine manner.