Characterization and rapid detection of adulterations in sesame oil using FT-MIR and PCA-LDA

The objective of this research work was to use Attenuated total reflectance-Fourier transform mid-infrared (ATR-FTMIR) spectroscopy coupled with chemometrics for the detection of the adulteration of sesame oil. Adulteration with sunflower oil, soybean oil or  colza oil  is one of the most difficult to detect due to the similar composition of them and sesame oil. Adulterations of sesame oil with different percentages of sunflower oil, soybean oil and colza oil were measured using ATR-FTMIR spectroscopy. The spectral data were subjected to a preliminary derivative elaboration based on the Savitzky–Golay algorithm to reduce the noise and extract a largest number of analytical information from spectra. Linear discriminant analysis (LDA) was adopted as classification method, and Principle component analysis (PCA) was employed to compress the original data set into a reduced new set of variables before LDA.The detection results indicated that the discriminant model built by PCA-LDA method could identify sesame oil adulterations in the 0–40% weight ratio range of edible oils, with an accuracy value of 94.64%. This work shows that PCA and LDA are useful chemometric tools for the multivariate characterization and discrimination of sesame oil adulteration with seed oils

Effect of different doses of gamma irradiation on biochemical and microbiological properties of sesame (Sesamum indicum L.) seeds

Seed irradiation during storage processes is one of the most effective methods to improve the seeds quality. This investigation was carried out to determine the effects of the different doses of ionizing radiation on biochemical and microbiological properties of sesame seeds and oil. To determine these effects, seeds were exposed to radiation with different doses 3, 6, 9 and 12 kGy to time period of 207, 413, 620 and 826 min respectively. The results showed that gamma irradiation had no significant (p>0.05) effect on the different parameters. The ionizing radiation has no negative effect on the biochemical and microbiological quality of seeds and sesame oils. On the contrary, irradiation at different doses preserves the properties of sesame throughout the duration of storage While, small differences, but sometimes significant (p<0.05), on protein and sugar contents were recorded between irradiated and non-irradiated samples. The samples irradiated with the different doses (3, 6, 9 and 12kGy) preserved a great antioxidative activity, a high phenolic, flavonoids and protein content during the 12 months of conservation. Also, gamma radiation has ensured great stability throughout the experiment with regard to acidity and peroxide index. While, for the microbiological parameters, all the samples treated with the different doses remained completely free of bacteria at the end of storage period (after 12 months)

Tocoferoles y fitoesteroles en semillas de girasol para consumo directo

Sunflower seeds for the human food market are derived from both oilseed-type cultivars, with black achenes and low hull proportion, and confectionery-type cultivars, with striped achenes and high hull proportion. The objective of this research was to evaluate tocopherol and phytosterol contents in the seeds of both types of cultivars. Five oilseed-type and seven confectionery-type cultivars were evaluated in replicated field trials in two locations of Morocco and Spain. Large variations were found in hundred-kernel weight (2.6 to 5.5 g), kernel oil content (42.7 to 67.5%), tocopherol content (203 to 397 mg kg–1 kernel), and phytosterol content (2179 to 3555 mg kg–1 kernel). Both types of cultivars did not differ for kernel weight, kernel oil content, or tocopherol and phytosterol profiles. However, oilseed-type cultivars had significantly greater average tocopherol and phytosterol contents, though confectionery-type cultivars with levels of tocopherols and phytosterols similar to the best oilseed-type cultivars were identified. The large variations in kernel tocopherol and phytosterol contents found in this research suggest that there is room for breeding for increased levels of these compounds in order to develop healthier sunflower cultivars for the human food market.Las semillas de girasol para consumo directo proceden tanto de cultivares oleaginosos, con aquenios negros y baja proporción de cáscara, como de cultivares de consumo directo, con aquenios de colores claros o rayados y elevada proporción de cáscara. El objetivo de este trabajo fue evaluar el contenido en tocoferoles y fitoesteroles en semillas de ambos tipos de cultivares. Se evaluaron cinco cultivares oleaginosos y siete cultivares de consumo directo en ensayos de campo replicados en dos localidades de Marruecos y España. Se identificó gran variación para peso de 100 semillas (aquenios descascarillados; 2.6 a 5.5 g), contenido en aceite en la semilla (42.7 a 67.5%), contenido en tocoferoles (203 a 397 mg kg–1 semilla), y contenido en fitoesteroles (2179 a 3555 mg kg–1 semilla). No se observaron diferencias entre ambos tipos de cultivares para peso de semilla, contenido de aceite en la semilla, o perfiles de tocoferoles y fitoesteroles. Sin embargo, los cultivares oleaginosos presentaron mayor contenido medio de tocoferoles y fitoesteroles, aunque se identificaron cultivares de consumo directo con niveles de estos compuestos similares a los mejores cultivares oleaginosos. La gran variación encontrada para contenido en tocoferoles y fitoesteroles sugiere la posibilidad de elevar los niveles de estos compuestos mediante mejora genética con el objetivo de desarrollar cultivares de girasol de consumo directo más saludables

Germination and Seedling Growth of a Set of Rapeseed (Brassica napus) Varieties under Drought Stress Conditions

Drought stress is one of the major abiotic factors affecting seed germination and plant growth especially in arid and semi-arid regions. In this study, we investigated the effects of drought stress on seed germination and seedling growth of five varieties of rapeseed. Seven drought stress levels of zero (control), -3, -5, -7, -9, -11 and -13 bars were performed using polyethylene glycol-6000 (PEG-6000). A completely randomized design with three replications was used for this experiment. Germination percentage (GP), germination rate (GR), mean germination time (MGT), root length (RL) and shoot length (SL) were measured to evaluate the varieties response to PEG-induced drought stress. Drought stress, variety and the interaction drought × variety had a significant effect on all studied parameters. GP and GR decreased with the increase in stress level, while MGT increased. There were no seeds germinated for all varieties at -11 bars and -13 bars. Shoot length decreased with increasing drought stress but different varieties show different performance under stress environment. Root length decreased with increasing level of severe drought stress. However, the presence of moderate drought stress could even improve the root growth of the investigated varieties. The varieties ‘INRA-CZH2' and ‘INRA-CZH3' exhibited the highest germination percentage and the best early seedling growth. Thus, they could be recommended for environments with early cropping cycle drought

Tocopherols and phytosterols in sunflower seeds for the human food market

Sunflower seeds for the human food market are derived from both oilseed-type cultivars, with black achenes and low hull proportion, and confectionery-type cultivars, with striped achenes and high hull proportion. The objective of this research was to evaluate tocopherol and phytosterol contents in the seeds of both types of cultivars. Five oilseed-type and seven confectionery-type cultivars were evaluated in replicated field trials in two locations of Morocco and Spain. Large variations were found in hundred-kernel weight (2.6 to 5.5 g), kernel oil content (42.7 to 67.5%), tocopherol content (203 to 397 mg kg&lt;sup&gt;–1&lt;/sup&gt; kernel), and phytosterol content (2179 to 3555 mg kg&lt;sup&gt;–1&lt;/sup&gt; kernel). Both types of cultivars did not differ for kernel weight, kernel oil content, or tocopherol and phytosterol profiles. However, oilseed-type cultivars had significantly greater average tocopherol and phytosterol contents, though confectionery-type cultivars with levels of tocopherols and phytosterols similar to the best oilseed-type cultivars were identified. The large variations in kernel tocopherol and phytosterol contents found in this research suggest that there is room for breeding for increased levels of these compounds in order to develop healthier sunflower cultivars for the human food market.&lt;br&gt;&lt;br&gt;Las semillas de girasol para consumo directo proceden tanto de cultivares oleaginosos, con aquenios negros y baja proporción de cáscara, como de cultivares de consumo directo, con aquenios de colores claros o rayados y elevada proporción de cáscara. El objetivo de este trabajo fue evaluar el contenido en tocoferoles y fitoesteroles en semillas de ambos tipos de cultivares. Se evaluaron cinco cultivares oleaginosos y siete cultivares de consumo directo en ensayos de campo replicados en dos localidades de Marruecos y España. Se identificó gran variación para peso de 100 semillas (aquenios descascarillados; 2.6 a 5.5 g), contenido en aceite en la semilla (42.7 a 67.5%), contenido en tocoferoles (203 a 397 mg kg&lt;sup&gt;–1&lt;/sup&gt; semilla), y contenido en fitoesteroles (2179 a 3555 mg kg&lt;sup&gt;–1&lt;/sup&gt; semilla). No se observaron diferencias entre ambos tipos de cultivares para peso de semilla, contenido de aceite en la semilla, o perfiles de tocoferoles y fitoesteroles. Sin embargo, los cultivares oleaginosos presentaron mayor contenido medio de tocoferoles y fitoesteroles, aunque se identificaron cultivares de consumo directo con niveles de estos compuestos similares a los mejores cultivares oleaginosos. La gran variación encontrada para contenido en tocoferoles y fitoesteroles sugiere la posibilidad de elevar los niveles de estos compuestos mediante mejora genética con el objetivo de desarrollar cultivares de girasol de consumo directo más saludables

Comparative study of four safflower oils (Carthamus tinctorius) varieties grown in eastern of Morocco

Safflower (Carthamus tinctorius) is an oilseed crop, which, for many years, has been grown on a relatively small scale in parts of North Africa and Middle East (Purdy and al., 1959)