に as a sentence ender.

[Lucas89]

I have tried searching google and the forums for this but I'm not quite sure what to search for so haven't really turned up any results.

I sometimes see the particle に used at the end of sentences.
But based on context etc. I know that this can't possibly be the に particle as I normally think of it.
Here is a sentence: うまい食べ物なら、人はまた同じものを食べるだろうに。
Is this just being used to add emphasis, or is there some hidden nuance that comes along with using it?

[magamo]

I don't know what you normally think of に, but if you're referring to に as in "ここに置いて下さい (Leave it here)," yes, they're different. The one you normally think of is technically 格助詞 (particle) and the に in your example is 接続助詞 (conjunction). If you have a grammar, I think you can find an entry for に as a conjunction. One of the usages of this kind of に carries a nuance of 逆説, or you could say it is adversative.

If this kind of grammar is too difficult and are using a textbook designed for foreigners, I think you can find a simplified grammar-ish explanation in a section explaining ...でもあるまいに, ...もあろうに, だろうに or something along those lines. Your textbook might treat them as idioms or set phrases.

If you just want a practical explanation for the sentence in your post, it's just a marker used when the speaker can't believe a statement or what has happened, and expresses a sense like "It can't be," "No way," "You shouldn't have done it..." "It shouldn't be this way..." etc. Here is an example sentence:

もっと上手くやれただろうに。(*sigh* You could do better than that...)

As for the meaning of your example sentence, it's impossible to know what the speaker actually implied by に because you didn't give context. But I guess it's "Huh? If you give them delicious food, they'd eat the same food again," "I don't think so. If it tasted good, people would eat it again," or the like.

[Hyperworm]

Isn't だろうに＝だろうのに?

[magamo]

Isn't だろうに＝だろうのに?

If you replace だろうに with だろうのに in the OP's sentence, it'd sound unnatural. Perhaps you're suggesting something different?

[Hyperworm]

I didn't quite mean that one is replaceable by the other ... actually I don't remember seeing だろうのに very much. I meant that where I'd expect to see だろう + のに, I find だろうに instead, so I thought perhaps だろうに comes from elision of だろうのに to make it easier to say.
Maybe I've been mistaken? ^^;

[keatonatron]

Maybe what Hyperworm was getting at is that your explanation for this に sounds just like the explanation for the ender のに.

(e.g.勉強すれば簡単に合格出来たのに)

Yes, you can't interchange these two, but is the nuance similar? (I too haven't come across だろうに before, from what I recall)

[magamo]

I didn't quite mean that one is replaceable by the other ... actually I don't remember seeing だろうのに very much. I meant that where I'd expect to see だろう + のに, I find だろうに instead, so I thought perhaps だろうに comes from elision of だろうのに to make it easier to say.
Maybe I've been mistaken? ^^;

Maybe what Hyperworm was getting at is that your explanation for this に sounds just like the explanation for the ender のに.

(e.g.勉強すれば簡単に合格出来たのに)

Yes, you can't interchange these two, but is the nuance similar? (I too haven't come across だろうに before, from what I recall)

Ah, I got it. のに is a stand-alone word in modern Japanese, but etymologically it is の + に, where "の" is 格助詞 (or 準体助詞) and "に" is 接続助詞.

Since だろうのに sounds quite unnatural, it isn't associated with だろうに in a native speaker's mind (Well, at least it isn't in my mind.). But if you think it's easier to understand だろうに as kind of だろうのに, then it might be ok to think so.

Edit: I almost forgot. If you say, "勉強すれば簡単に合格出来ただろうに…," usually the speaker isn't the person who would have passed the exam (there are lots of exceptions, though.). But if you use "勉強すれば簡単に合格出来たのに…," either the speaker or another person can be the subject. The nuances are pretty much the same in this case.

[Lucas89]

Thank you for your explanations.

Unfortunately I don't have a text book so I can't look things like this up (I say unfortunately... I don't have one because I hate text books with a passion)
However I have ordered some grammar dictionaries recently, so when they arrive I will take a look through them too.

It's nice to kind of have an idea of what it now means anyway