Introduction
Oil–bearing crops include those whose fruits (or mesocarps), seeds, and
nuts are worth for the edible or industrial oils to extracted. The Food
and Agriculture Organization of the United Nations (FAO) listed 21 oil
crops, which collectively yield an annual production of world oilseed
for about 100 million tons (Athar and Nasir, 2005). Vegetable oils have
progressively supplanted animal oils as a major source of dietary fat,
leading to oil crop production becoming one of the prevailing forms of
world agriculture. Oil crops contain diverse array that strengthen
nutritional value of human diet, with the oils generated by such crops
being especially good sources of tocopherol and thus promoting the
balanced intake of vitamin E (Athar and Nasir, 2005; Kornsteiner et al.,
2006). Peanuts, most fundamental food crop in the world, where China,
India, and the United States are top three peanuts worldwide producers
(Arya et al., 2016). The peanuts pods ripen approximately 150 days after
the seeds planted. With mechanized reaping, the whole peanut plant,
including the seed pods, are removed from the soil before being dried
(sun or hot–air) and then seed shelling (Arya et al., 2016; Nawade et
al., 2018). Peanuts easily lipid oxidize and decompose during storage
and transportation due to their high–fat level (>50%),
and this influence their nutritional, agricultural and edible safety
importance (Chukwumah et al., 2007; Liu et al., 2018; Hu et al., 2019;
Xie et al., 2019).
The cooking methods used with edible oils differ in terms of the
temperature, duration, and the amount of oil used. Vegetable oils are
important constituents of the daily diet of most people, although the
actual intake of such oils differs considerably depending on the cooking
methods used. The World Health Organization (WHO) has identified three
important factors for determining the nutritional value of oils: I) the
presence of antioxidants; II) the ratio of saturated fatty acids (SFA),
mono–unsaturated fatty acids (MUFA), and poly–unsaturated fatty acids
(PUFA); and III ) the essential fatty acid ratio (Hashempour–Baltork et
al., 2016). Relatedly, the WHO has recommended a ratio of 1:1.5:1 for
SFA:MUFA: PUFA and a ratio of 1:5~10 for α– linolenic
acid (omega–3): linoleic acid (omega–6) in people’s dietary intake.
Vegetable oils are high in MUFA and, as part of a low–cholesterol diet,
have been found to lead to reduced cardiovascular disease (CVD) risk, in
addition to potentially improving serum lipid profiles, decreasing LDL
oxidation, and exerting a cardioprotective effect (Hashempour–Baltork
et al., 2016; Chen et al., 2008). The antioxidant components in
vegetable oils is composed of hydrocarbons, carotenes, tocopherol,
phytosterols, and triterpenes, the minor constituents of various
vegetable oils are associated with medicinal qualities and thus can be
useful in preventing or delaying the onset of chronic diseases and
promoting health (Chen et al., 2008; Alasalvar and Bolling, 2015; Ghosh
et al., 2017).
Organic solvent extraction (mostly using petroleum ether, petroleum
benzene, and hexane) and mechanical pressing are two conventionally used
commercial methods in producing vegetable oils. However, the residual
solvent remains of the former process can cause environmental safety
issues and neurological damage, while mechanical pressing provides only
a low yield of oils (Mingyai et al., 2018; Yang et al., 2018). To
increase the extractability of oil, several destructive pretreatments
need to be performed. Cold‐pressed oils are generated with no refining
process and have good flavor, stable quality, and are high in bioactive
components, qualities which have led them to be regarded as excellent
food oils by consumers (Yang et al., 2018). Roasting, grinding, and
pressing have been the key steps in peanut oil processing. Recent
research findings, however, have given mind to the enhancement of
substitute processing techniques for oil production and flavor. Roasting
constitutes a critical processing stage that affect the color,
composition, conversion to bioactive compounds, and or ganoleptic
qualities of the extracted oils, as well as their oxidative stability
(Chang et al., 2016; Taş and Gökmen, 2017; Różańska et al., 2019).
Research has shown, for example, that roasting increases the oxidative
stability of sesame oil, with no oxidation being observed for 50 days
after roasting (Rostami et al.,2014).
Insufficient information regarding edible oils has made it increasingly
difficult for consumers to choose oils for purchase. Traditional peanut
oil preparation focuses on the relationship between roasting temperature
and aroma but ignores thermal-oxidative degradation and active
substance. In this study, peanuts were roasted at different temperatures
(120, 140, and 160℃) to determine how those roasting temperatures affect
the chemical properties related to the quality of the oils generated. We
investigated various quality indices and the oxidative stability of the
generated peanut oils, as these factors have received increasing
attention as edible oils have been increasingly recognized as a
necessary source of antioxidant components in a healthy balanced diet.
Relatedly, the obtained data should be useful for deepening the
understanding of the chemical profile, in addition to providing
scientific evidence for enhancing the human diet qualities. Moreover,
this present work may serve as a worth reference for future
complementary studies aimed at evaluating the beneficial effects of
vegetable oils on human health.