A comprehensive study of raw and roasted macadamia nuts: Lipid profile, physicochemical, nutritional, and sensory properties

Abstract

Macadamia nuts have high nutritional value and positive health attributes. Changes to the composition and availability of these compounds during roasting contribute to product quality. In this study, changes to the chemical composition of lipids (fatty acids, triglycerides, and free fatty acids) and other phytochemicals were analyzed, and a sensory evaluation was carried out of two major varieties of macadamia nuts planted in China, after roasting. Only small changes in fatty acid (FA) content and a slight decrease in total triglycerides (TAGs) were observed after roasting. The free fatty acid (FFA) content and the peroxide value were increased by roasting. The total available polyphenol content increased by 25.6% and the oxidative stability index of kernels increased by 21.6%. The sensory scores for taste and aroma were doubled by roasting. Overall, the sensory, nutritional quality, and oxidative stability of roasted macadamia nuts were greatly improved, compared with raw nuts.

Flavor and compositional analysis of macadamia nuts during long‐term storage

“…Besides, the most direct way to evaluate flavor as it can be accepted by human beings is to carry out a sensory analysis. The sensory quality of macadamia nuts was evaluated by sensory description analysis and the main flavor attributes were as follows: fruity, creamy, grassy, rancid, pungent (Franklin & Mitchell, 2019; Tu et al, 2021). There were no similarities for the flavor attributes when used to describe the odor profile of macadamia nuts.…”

“…Several reactions of nutrients are considered to be the source of volatile compounds in macadamia nuts. It was reported that carefully controlled thermal processing can enhance the flavor of macadamia nuts through Maillard reactions and lipid oxidation (Tu et al, 2021).…”

Combined Transcriptome and Lipidomic Analyses of Lipid Biosynthesis in Macadamia ternifolia Nuts

“…TAGs are the primary components of Macadamia oil, accounting for more than 95% of total lipids. These influence the nutritional characteristics of nut oil through physical and biochemical changes [42]. TAGs are entirely acylated derivatives of glycerol and the most abundant neutral lipid bodies present in seeds [43], senescence leaves, and pollen grains [44,45].…”

“…Free fatty acids are more vulnerable to oxidation during nut roasting, which causes adverse chemical changes through rancidity and the deterioration process, which ultimately leads to rejection by consumers due to a lower quality of nuts [53]. In a recent study, it was observed that roasting had a non-significant impact on the TAGs composition and it ultimately improved the flavor, aroma, color, texture, and appearance of macadamia nuts [42]. Among other detected glycerolipids in the developing fruit kernels of M. ternifolia, different species of diacylglycerols (DAGs) have a high abundance.…”

In silico analysis of novel dipeptidyl peptidase-IV inhibitory peptides released from Macadamia integrifolia antimicrobial protein 2 (MiAMP2) and the possible pathways involved in diabetes protection

“…Macadamia integrifolia and Macadamia tetraphylla trees are members of the family Proteaceae that occurs naturally in subtropical Australia rainforests. In recent years, the planting area of macadamia in China is about 160,000 ha, mainly centered in Yunnan and Guangxi provinces ( Tu et al, 2021 ). Macadamia nuts are popular snack foods, and are rich in fat (∼75%) and protein (∼8%) ( Gwaltney-Brant, 2013 ).…”