Janissaries having a spoon attached to their börk

[druzhina345]

During what period did Janissaries have a spoon attached to their börk, or in their plume holder?
An early mention of this is in Miller's The Costume of Turkey, 1802, to accompany illustrations of Ottomans after Octavien d'Alvimart

Ladle Bearer

The Janissaries themselves, also, have a wooden spoon, with which they eat their pilàv, and which they wear in their caps instead of feathers ; and they as much look upon these as a part of the military dress, as an European would a sword.

In McLean's The Military Costume of Turkey, 1813 it appears as
Ladle Bearer

In strict conformity with such ideas of military parade, the Janizaries have each of them a wooden spoon, wherewith they eat their pilau, and which they wear instead of a feather, stuck into a copper tube, which is affixed in front of their bonnets.

Miller's text was based on various sources (Baron De Tott, J. Dallaway, G.A. Olivier, M. Montague, J. Pitton de Tournefort, M. d’Ohsson, etc.)
After searching I found it in one:
Constantinople Ancient and Modern: With Excursions to the Shores and Islands of the Archipelago and to the Troad by James Dallaway, 1797:

On days of gala the janissaries wear a large felt cap, certainly of Egyptian invention, with a square piece falling down behind and covering half their back; in front is a socket of copper, originally intended to carry feathers, which they bore in honour of any signal feat in war, but lately to hold a wooden spoon for their pilàv; for a good janissary considers his spoon to be as military an accoutrement as an European would his sword or bayonet.

So if this was only a custom adopted lately, it would not have been the case in earlier centuries.

Travels of Ali Bey in Morocco, Tripoli, Cyprus, Egypt, Arabia, Syria, and Turkey. Between the years 1803 and 1807 has

The janissaries of the guard wear, as do all the Turks, a long robe, but of different colours, each according to his taste, without any other sign of distinction, than an extravagant cap of greyish white felt, the hinder part of which hangs behind and covers the back; there is a plate of metal before, which falls upon the forehead, and encloses, as if in a case, a wooden spoon of a rude shape, which each janissary is obliged always to carry with him.

Are there any earlier mentions of this practice? The plume holder would have only been called a Kaşıklik (spoon receptacle) after this became a practice.

Druzhina345
Illustrationsof Ottoman Janissaries