A very unusual usage for uncompromising, which means अटल, अनम्य, दृढ़ and the phrase will be (literally) translated as:

अटल स्वाद or अनम्य स्वाद or दृढ़ स्वाद

None of these, I must admit, makes sense.

Do you have more context?

The word "uncompromising" generally would not be used as an adjective for flavour.

--------------------------------------------------
Note added at 1 hr 26 mins (2005-07-21 09:20:31 GMT)
--------------------------------------------------

I would read it as \"uncompromising in quality\" of the product or uncompromising in the sense of it being true to the original. If such a sense is indeed the case, the pharase can be translated as:

एकदम शुद्ध स्वाद
or
परिशुद्ध स्वाद

--------------------------------------------------
Note added at 1 hr 53 mins (2005-07-21 09:47:35 GMT)
--------------------------------------------------

In the light of the added context असली (asli) in the meaning of original is a word that you can consider using. Here is my try of the whole translation, for what it is worth:

It has an unforgettable fragrance and uncompromising flavour - the true sign of 100% pure basmati

उसकी अपूर्व सुगंध एवं बेमिसाल स्वाद मन में बस जाते हैं। शत-प्रतिशत शुद्ध बासमती की असली पहचान भी तो यही है।

The word "shudh" indicates something that is pure, without additives, which would meet the "uncompromising" quality of the stuff in question. And by now, it is clear that "swad" refers to flavour, taste, etc.

Sabse Ooncha signifies that it is " NOT LESS " anywhere.

I agree with Arun and Bala above. We can't afford to translate it literally here as it would sound peculiar, formal and even funny. Since this relates to the advertisement world, the translation should be attractive and catchy rather than bookish and rough.

Your sentence:

Isme manbhAvan khushboo hai aur iskA swAd bejod hai - sau pheesadii khare bAsmatii kii yahii aslii nishAnii hai

इसमें मनभावन खुश्बू है और इसका स्वाद बेजोड़ है - सौ फीसदी खरे बासमती की यही असली निशानी है।

I have resisted the temptation of using pure Hindi words as that might
adversaly affect the flow. Instead, I have used colloquial words so that it may influence the masses.

--------------------------------------------------
Note added at 5 hrs 53 mins (2005-07-21 13:47:51 GMT)
--------------------------------------------------

The second suggestion has missed to appear for unknown reasons. In fact, I have mentioned LAjwAb swAd लाजवाब स्वाद as the second alternative.

--------------------------------------------------
Note added at 19 hrs 44 mins (2005-07-22 03:38:38 GMT)
--------------------------------------------------

Some more attempts of Free Translation:

(Pure Hindi Tone)

Isme avismarNiya sugandh hai aur iskA swAd anupam hai, poorNatAh shudh bAsmati isii visheshtA ke kAraN jAnA jAtA hai.

इसमें अविस्मरणीय सुगंध है और इसका स्वाद अनुपम है, पुर्णतः शुद्ध बासमती इसी विशेषता के कारण जाना जाता है।

Another suggestion:

Iski khushboo man ko besudh kar detii hai aur iskA zAikA lAjwAb hai, poorii tarAh say kharA bAsmatii isii khAsiyat ki wajah say jAnA jAtA hai.

इसकी खुश्बू मन को बेसुध कर देती है और इसका ज़ायका लाजवाब है, पूरी तरह से खरा बासमती इसी खासियत की वजह से जाना जाता है।

Literally.