Effect of Roasting Temperatures on the Properties of Bitter Apricot (<i>Armeniaca sibirica</i> L.) Kernel Oil

Abstract

Volatile compounds and quality changes of bitter apricot (Armeniaca sibirica L.) kernel oil (AKO) with different roasting conditions were determined. Bitter apricot kernels were roasted at 120, 130, 140 and 150°C for 15 min. Unroasted bitter apricot kernel oil was used as the control. Quality indicators included color, acid value and peroxide value, fatty acids, total phenols and oxidative stability. Peroxide values of the tested oils were 0.46-0.82 meq/kg, acid values were 0.60-1.40 mg KOH/g, and total phenol contents were 54.1-71.5 μg GAE/g. Oleic acid was the major fatty acid, followed by linoleic, palmitic, stearic and palmitoleic acids. Roasting increased the oxidative stability of bitter AKO. Volatile compounds were tentatively identified and semi-quantified. Among the 53 volatiles identified, benzaldehyde and benzyl alcohol were the major components. These two aroma compounds increased significantly during roasting and contributed sweet and almond flavors. Pyrazines were also prevalent and significantly increased with roasting. Sensory evaluation showed that roasted, nutty, sweet and oily aromas increased as roasting temperature increased.Practical applications: Bitter apricot kernels cannot be consumed directly, thus it is potentially beneficial to find uses for them, especially in China where bitter apricot processing is a significant industry. Roasted bitter AKO with a pleasant aroma could be prepared and might find use as an edible oil. The roasting process gave the bitter AKO a pleasant flavor. This study provided preliminary information on production parameters and potential quality control parameters.

Effect of roasting pre‐treatment of two grafted pine nuts ( Pinus koraiensis ) on yield, color, chemical compositions, antioxidant activity, and oxidative stability of the oil

“…The L *, a *, and b * values of oil from unroasted pine nut kernels were 95.92, −5.12, 46.42, and 95.79, −5.49, 57.78 for the PK and PKS samples, respectively. The a * and b * values increased significantly ( p < .05), while the L * value decreased significantly ( p < .05) for both varieties by increasing the roasting time and temperature, and the trends in color values were in accordance with a study for oils from roasted bitter apricot kernels (Jin et al., 2018). The L * values did indeed decrease as roasting temperatures rose in the PK and PKS samples, and reached the minimum values at 180℃ for 30 min, which were 59.12 and 57.1, respectively.…”

“…A similar trend was also found in p‐AV (Figure 1c,f), suggested the increase in the content of primary and secondary oxidation compounds. In summary, the oxidative stability of pine nut oil could be enhanced by appropriate roasting treatment, and similar results could be found in the researches for pistachio oil (Rabadán et al., 2018) and apricot kernel oil (Jin et al., 2018). The improved oxidative stability of oil from roasted pine nuts could be attributed to the synergistic antioxidant effect of browning substances that were produced in the roasting process and increased bioactive compounds.…”

Effects of different preheat treatments on volatile compounds of camellia ( Camellia oleifera Abel .) seed oil and formation mechanism of key aroma compounds

“…The study has shown that the composition and content of volatile compounds in peanut oil changed significantly after roasting pretreatment, and the contents of O‐heterocyclic compounds and N‐heterocyclic compounds accounted for a relatively high proportion, of which 20 pyrazines were considered as key contributors to the typical nut and roasting aroma of peanut oil (Liu et al., 2011). Similar studies have been done in sesame oil, rapeseed oil, palm kernel oil, almond oil, pumpkin seed oil, and peony seed oil (Jin et al., 2018; Jin et al., 2019; Jing et al., 2020; Potočnik & Košir, 2017; Yan et al, 2012; Zhang et al., 2016). Microwave, as a new heating technology, is gradually applied to oil processing.…”

Effect of roasting temperature and time on volatile compounds, total tocopherols, and fatty acids of flaxseed oil

“…Free amino acids and monosaccharides are considered important flavor precursors for the formation of volatile compounds with unique flavors, such as pyrazine, during roasting (Marzocchi et al., 2017). A previous study showed that pyrazines are typical volatile compounds detected in roasted seeds, including bitter apricot kernel, hazelnut, sesame seeds, peanut, and so on (Jin et al., 2018; Marzocchi et al., 2017; Park et al., 2011). In the present study, five pyrazines were identified: 2‐methylpyrazine, 2,5‐dimethylpyrazine, 2,3‐dimethyl‐5‐ethylpyrazine, 2‐ethyl‐6‐methylpyrazine, and 2,6‐dimethylpyrazine.…”