Analyzing the Effect of Baking on the Flavor of Defatted Tiger Nut Flour by E-Tongue, E-Nose and HS-SPME-GC-MS.

Quanhong Li,Tingting Liu,Yanrong Zhang,Dawei Wang,Chunbo Guan

doi:10.3390/foods11030446

Abstract

In order to screen for a proper baking condition to improve flavor, in this experiment, we analyzed the effect of baking on the flavor of defatted tiger nut flour by electronic tongue (E-tongue), electronic nose (E-nose) and headspace solid-phase microextraction gas chromatography-mass spectrometry (HS-SPME-GC-MS). According to E-tongue and E-nose radar plots and principal component analysis (PCA), baking can effectively change the taste and odor of defatted tiger nut flour, and the odors of samples with a baking time of >8 min were significantly different from the original odor of unbaked flour. Moreover, bitterness and astringency increased with longer baking times, and sweetness decreased. HS-SPME-GC-MS detected a total of 68 volatile organic compounds (VOCs) in defatted tiger nut flour at different baking levels, and most VOCs were detected at 8 min of baking. Combined with the relative odor activity value (ROAV) and heat map analysis, the types and contents of key flavor compounds were determined to be most abundant at 8 min of baking; 3-methyl butyraldehyde (fruity and sweet), valeraldehyde (almond), hexanal (grassy and fatty), and 1-dodecanol, were the key flavor compounds. 2,5-dimethyl pyrazine, and pyrazine, 2-ethylalkyl-3,5-dimethyl- added nutty aromas, and 1-nonanal, 2-heptanone, octanoic acid, bicyclo [3.1.1]hept-3-en-2-ol,4,6,6-trimethyl-, and 2-pentylfuran added special floral and fruity aromas.

Highlights

Tiger nut (Cyperus esculentus L.), known as wild chestnut, underground walnut, etc., is a highly efficient and high-quality edible oil crop that is drought-resistant [1]
With this work, we offer a theoretical basis for the flavor improvement of starchy raw materials such as defatted tiger nut flour, through baking
Reasonable baking can effectively improve the flavor of defatted tiger nut flour

Summary

Introduction

Tiger nut (Cyperus esculentus L.), known as wild chestnut, underground walnut, etc., is a highly efficient and high-quality edible oil crop that is drought-resistant [1] It originated in North Africa and the Mediterranean, and is widely cultivated in Spain, Italy, South Africa, and other regions [2]. As a by-product of tiger nut oil production, defatted tiger nut flour contains many nutrients such as starch, sugar, dietary fiber, protein, vitamins, and minerals [5,6]. It is a raw material for low-fat food with high nutritional value. The oil contains much flavor [7], but as most of the oil in the tiger nut is extracted, the fat-soluble flavor compounds are removed in the production of flour, resulting in the reduced flavor of the defatted flour

Methods

Results

Conclusion