Chapati is usually eaten within minutes of cooking, because it hardens as it keeps. A study on inhibiting chapati staling puts the industrial problem plainly: large-scale, mechanised production of ready-to-eat chapatis has to solve it.

What staling is

Staling happens when starch chains, gelatinised during cooking, begin to reassociate into an ordered structure. A study in Food Chemistry followed chapatis for a month at room and refrigerated temperatures. Over that time, moisture, water-soluble starch and enzyme digestibility fell steadily, the energy measured by calorimetry rose, the texture became progressively harder at both temperatures, and sensory quality declined.

What "leathery" means in numbers

Chapati texture is often measured by stretching a strip until it tears. In a study of composite flours and additives, extensibility and the energy needed to tear a chapati fell over 24 hours of storage. In rice flour chapatis, the force needed to tear them and their stiffness rose as well. A stale chapati stretches less and resists more, which is exactly what the mouth reads as leathery.

What slows it down

Enzymes. A study in LWT treated chapati doughs with fungal alpha-amylase, bacterial alpha-amylase, xylanase, and bacterial amylase with xylanase. All gave chapatis that needed significantly less force to shear than the controls, meaning softer chapatis. Chapatis made with bacterial alpha-amylase also had more soluble amylose, which is worth watching: a heat-stable amylase that keeps working after cooking can make the texture gummy.

Emulsifiers, humectants and hydrocolloids. The study on inhibiting staling tested sodium stearoyl lactylate, glycerol monostearate, propylene glycol, sorbitol, alpha-amylase, xylanase, maltodextrin and guar gum in chapatis stored for 10 days at 29 °C and 4 °C, and found that additives in this group slowed staling.

Hydrocolloids in gluten-free chapatis. In rice flour chapatis, guar, xanthan, locust bean gum and HPMC improved texture by keeping the chapatis extensible, and fungal amylase improved them further.

Barley beta-glucan. Adding barley flour or beta-glucan to wheat chapatis had anti-staling effects, and raised the water the dough absorbed.

The flour matters

A study of stone milling varied the mill aperture, feed rate and grain moisture, and produced flours with damaged starch from 6.1% to 26.9%. Those differences changed dough stickiness and chapati quality. Two flours with the same name can behave very differently, which is why a softness trial should record the flour's specification alongside everything else.

For ready-to-eat chapatis

  • Measure softness at fixed ages, by a stretch or shear test and a small panel, not by feel alone.
  • Record moisture, because moisture loss and starch staling both harden the chapati.
  • Test enzymes and hydrocolloids as separate trial arms against a control made the same day.
  • Store samples in the real pack at the real temperature.
  • Record the flour specification, including damaged starch where you can.