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Spectroscopic analysis of chia seeds
(Scientific Reports, 2021) Monica Mburu, Olivier Paquet‑Durand, Bernd Hitzmann & Viktoria Zettel
Chia seeds are becoming more and more popular in modern diets. In this contribution NIR and
2D-fluorescence spectroscopy were used to determine their nutritional values, mainly fat and protein
content. 25 samples of chia seeds were analysed, whereof 9 samples were obtained from different
regions in Kenya, 16 samples were purchased in stores in Germany and originated mostly from South
America. For the purchased samples the nutritional information of the package was taken in addition
to the values obtained for fat and protein, which were determined at the Hohenheim Core Facility. For
the first time the NIR and fluorescence spectroscopy were used for the analysis of chia. For the spectral
evaluation two different pre-processing methods were tested. Baseline correction with subsequent
mean-centring lead to the best results for NIR spectra whereas SNV (standard normal variate
transformation) was sufficient for the evaluation of fluorescence spectra. When combining NIR and
fluorescence spectra, the fluorescence spectra were also multiplied with a factor to adjust the intensity
levels. The best prediction results for the evaluation of the combined spectra were obtained for
Kenyan samples with prediction errors below 0.2 g/100 g. For all other samples the absolute prediction
error was 0.51 g/100 g for fat and 0.62 g/100 g for protein. It is possible to determine the amount of
protein and fat of chia seeds by fluorescence and NIR spectroscopy. The combination of both methods
is beneficial for the predictions. Chia seeds from Kenya had similar protein and lipid contents as South
American seeds.
Health Potential of Chia (Salvia hispanica L.) SeedsDerived α-linoleic Acid and α-linolenic Acids: A Review
(European Journal of Agriculture and Food Sciences, 2021-07-08) Josiah Oyalo and Monica Mburu
The desirability of functional foods proceeds alongside non-communicable
epidemic; diabetes, cardiovascular diseases, obesity and interrelated risk
factors. Consequently, research on chia seeds (Salvia hispanica L.) has
increased not only as seeds but also as oil due to their rich functional and
nutritional proprieties. Chia seed is rich in essential fatty acids such as αlinolenic (ALA) and α-linoleic acids (LA) with ALA being the biological
precursor to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
ALA is a plant-based essential omega-3 polyunsaturated fatty acids that must
be obtained through the diet since humans do not possess the enzymes to
synthesize the compound. The objective of this review was to identify the
beneficial effects of chia seeds derived ALA and LA on human health. From the
articles reviewed; it was observed that ALA and LA from chia seed could offer
benefits for example; anti-obesity, improvement in glucose homeostasis, athletic
performance, and anti-cholesterolemic effects and maintenance of healthy
serum lipid level. Furthermore, some articles reported anti-inflammatory, antiproliferative and apoptotic effects and anti-oxidant activity, which could
strengthen the prevention of chronic diseases. Although these benefits are
appealing to humans, mechanistic cell culture and animal models are required
to enhance our knowledge on their mode of action.
The Role of Chia Seeds Oil in Human Health: A Critical Review
(European Journal of Agriculture and Food Sciences, 2021-07-06) Monica Mburu
Chia, Salvia hispanica L., is emerging as an important functional food
ingredient because of its rich contents of dietary fiber, omega‐3 fatty
acids and an indicative source of bioactive peptides owing to its high
concentration of proteins and essential amino acids. The use of food with
nutraceutical and functional properties for management of lifestyle
diseases like diabetes, obesity, and cardiovascular problems is now
gaining momentum among the public. Current research findings reveal
high nutritive value for chia seeds and their oils validating their massive
health-promoting properties. Currently chia is consumed as seeds and
oil with similar effects. The oil is rich in in polyunsaturated fatty acid, αlinoleic acid, the biological precursor to docosahexaenoic acid and
eicosapentaenoic acid. It has been scientifically established that chia is
an immune improver and has therapeutic effects on control of diabetes,
dyslipidemia, hypertension, as anti-inflammatory, antioxidant, antiblood clotting, laxative, antidepressant, antianxiety, analgesic and vision.
This article provides a review of the role of chia seeds oil in human
health. The Phytochemical characteristics of chia oil is presented and the
effect of their consumption on human health is discussed.
Chia Oil Adulteration Detection Based on Spectroscopic Measurements
(MDPI, 2021-08-04) Monica Mburu, Clement Komu, Olivier Paquet-Durand, Bernd Hitzmann and Viktoria Zettel
Chia oil is a valuable source of omega-3-fatty acids and other nutritional components.
However, it is expensive to produce and can therefore be easily adulterated with cheaper oils to
improve the profit margins. Spectroscopic methods are becoming more and more common in food
fraud detection. The aim of this study was to answer following questions: Is it possible to detect
chia oil adulteration by spectroscopic analysis of the oils? Is it possible to identify the adulteration
oil? Is it possible to determine the amount of adulteration? Two chia oils from local markets were
adulterated with three common food oils, including sunflower, rapeseed and corn oil. Subsequently,
six chia oils obtained from different sites in Kenya were adulterated with sunflower oil to check the
results. Raman, NIR and fluorescence spectroscopy were applied for the analysis. It was possible to
detect the amount of adulterated oils by spectroscopic analysis, with a minimum R2 of 0.95 for the
used partial least square regression with a maximum RMSEPrange of 10%. The adulterations of chia
oils by rapeseed, sunflower and corn oil were identified by classification with a median true positive
rate of 90%. The training accuracies, sensitivity and specificity of the classifications were over 90%.
Chia oil B was easier to detect. The adulterated samples were identified with a precision of 97%. All
of the classification methods show good results, however SVM were the best. The identification of
the adulteration oil was possible; less than 5% of the adulteration oils were difficult to detect. In
summary, spectroscopic analysis of chia oils might be a useful tool to identify adulterations
Physicochemical Profile of Essential Oils Obtained from Chia (Salvia hispanica L.) Seeds Grown in Different Agro-Ecological Zones of Kenya
(European Journal of Advanced Chemistry Research, 2021-08-15) Clement Komu, Monica Mburu, Daniel Njoroge, and Richard Koskei
The chia seed samples were purchased from farmers in five locations in three
agro-ecological zones in Kenya. The oil was obtained by cold pressing and
physicochemical properties were determined; the fatty acid profile was
determined by Gas chromatography. The mean oil yield from pressing was
16%, the refractive index of chia seed oil at 25 °C ranged from 1.4811 to 1.4832,
specific gravity ranged from 0.9616 to 0.9629, acidity index and free fatty acids
content ranged from 0.0345-0.0808 mg KOH/g oil, and 0.1736-0.4061%,
respectively. The matter in volatiles ranged from 0.047-0.086%. The
saponification value ranged from 162.1969–183.3791 milligrams (mg) of
potassium hydroxide (KOH) per gram (g) of chia seed oil. The differences in
refractive index, acidity index, free fatty acids, specific gravity, and
saponification value, were statistically significant at (P<0.05). The α-linolenic
(C18:3) and linoleic acids (C18:2) were the dominant fatty acids in chia seed oil
and they varied with regions. The levels α-linolenic (C18:3) and linoleic acids
(C18:2) ranged from 53.32-64.04% and 19.37-22.87%, respectively. The levels
of oleic, linoleic, and linolenic fatty acids in chia seed oils from different regions
were statistically significant at (P<0.05). The study recommended the
cultivation of chia seed in agro-ecological zones II and III where higher yields
and higher content of linoleic and linolenic fatty acids were reported,
consumption of chia seed oil as edible oil, and substitution of marine oils with
chia oil as potential sources of polyunsaturated fatty acids.
