Under the laws of the UK and countries whose legal system is derived from English Common Law, which includes the United States, the dead cannot be libelled. So in those countries using this man as a character will not get you into legal trouble, whatever you say about him. I do not know about the laws in non-Anglosphere countries.
(I assume that by "get into trouble" you mean legal trouble. An unflattering portrait of Henri Nestlé might, of course, upset any living relatives. I don't know anything about this man or what you plan to say about him, but as a general observation, I think an author ought to strive to be fair - which need not exclude criticism - to the reputation of real people, dead or alive, even if the author is safe legally whatever he or she does.)
Of course the Nestlé company still exists today. To imply that the company has been acting illegally or immorally in the present day or recent years might well be considered libellous and given certain controversies about infant formula I bet they have a vigilant legal team. However I cannot believe there would be a problem with what the company was doing in 1890 or even further back.
Please note that libel can still occur even if the reference to the person or organisation libelled is indirect, coded, or parodic.
Disclaimer: I am not a lawyer.