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Before peeling an orange, some people press the fruit firmly between their palms, or against a hard, flat surface, and roll it all around for several seconds. This is done in the belief that it helps loosen the peel from the flesh. I have tried this myself but can't say for sure whether it has any effect.

Is there, in fact, any non-anecdotal evidence that this procedure makes oranges easier to peel by hand? (By "easier", I mean that the peeling goes faster, or is less messy, or removes more of the pith.) Or is massaging oranges just time-wasting voodoo?

I'm aware that there are convenient peeling techniques that use a knife or a specialized tool but for this question I'm just interested in the case where all you have to work with is your hands.

Psychonaut
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Massage doesn’t work, because peel adhesion is structural. See J K Burns, ‘Citrus Fruit Abscission’ (Short Course and Workshop on Citrus Flowering, Citrus Research and Education Center, Lake Alfred, 1997). The white albedo layer is rich in pectin, cellulose and hemicellulose, which firmly bond the flavedo (colored outer rind) to the endocarp (juice segments). These bonds weaken naturally only as the fruit ripens or when specific enzymes (e.g. polygalacturonases) activate in the abscission zone.

Manual pressure is insufficient. Short of damaging the peel or pith (and squeezing out juice), palm-rolling exerts too little force to break these cell-wall bonds.

But here are 2 proven treatments that work!

1. Steam blanching

See Xian Shao, Hong Chen, Haibing Pan, Mark A Ritenour, Cuifeng Hu, Qinchao Xu & Xiulan Bao, ‘Effect of steam blanching on peelability and quality of Citrus reticulata Blanco’ (2020) 58 Journal of Food Science and Technology 3790.

Steam blanching with a 2-min duration showed the best peelability of citrus fruits with minimal quality changes, followed by optimal cooling in less than 5 min.

2. Enzymatic peeling

See María Teresa Pretel, Paloma Sánchez-Bel, Isabel Egea & Félix Romojaro, ‘Enzymatic Peeling of Citrus Fruits: Factors Affecting Degradation of the Albedo’ (2008) 2(1) Tree & Forestry Science & Biotechnology (Special Issue 1) 52.

A novel process, including heat treatment prior to enzymatic treatment, is proposed to peel persimmon fruit. Heat treatment induces fine and even cracks on the fruit surface … which act as channels via which enzyme solution can enter the peel tissue.

user196764
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