Influence of water stress and storage time on preservation of the fresh volatile profile of three basil genotypes

Effects of different drying processes on the quality changes in Arapgir purple basil (Ocimum basilicum L.) leaves and drying-induced changes in bioactive and volatile compounds and essential oils

The aim of this research is to examine the effects of drying purple basil leaves (Ocimum basilicum L.) under different drying conditions (freeze drying, sun-drying, and convective drying [CD] at 45, 50, and 55°C and microwave drying at 350, 460, and 600 W) on color properties, total phenolic and anthocyanin content, antioxidant activities, and changes in the composition of volatile compounds and essential oils (EOs). Increasing the drying temperature and microwave power led to an improvement in the preservation of the total phenolic content of the samples by an average of 16.28% and 27.98%, respectively. Increasing the drying temperature resulted in lower anthocyanin content and antioxidant activity (AA); in contrast, increasing the microwave power resulted in higher anthocyanin content and AA when drying purple basil. The drying methods significantly changed the composition of volatiles and EOs, and microwave drying resulted in a different profile of volatiles and EO composition. The key volatile compounds in purple basil leaves were linalol (81.19-1176.09 µg/g dw), 1,8-cineole (45.15-816.16 µg/g dw), and methyl cinnamate (13.20-637.65 µg/g dw). On the other hand, methyl cinnamate (11.68%-57.66%) and linalool (0.02%-20.39%) were the main volatile compounds of EOs in basil leaves. In conclusion, the following drying methods are suitable for the protection of phenolic and anthocyanin compounds and high performance of AA: freeze drying, sun-drying, and CD at 45°C and microwave drying at 600 W.

Coconut milk treated by atmospheric cold plasma: Effect on quality and stability

Commercial sterilization plays an important role in extending the shelf-life of coconut milk. However, thermal sterilization affects the quality of coconut milk. This study was initiated to evaluate the effects of atmospheric cold plasma (ACP) treatment on some important quality parameters of coconut milk. ACP treatment had a slight effect on physicochemical characteristics and nutritional ingredients while it obviously reduced the colony count. Furthermore, ACP treatment obviously promoted the formation of lactone, an indispensable volatile substance in coconut milk. Insufficient or moderate ACP treatment had subtle effect on the sensory quality. Notably, moderate ACP treatment reduced the droplet size from 28.0 μm to 18.6 μm, and improved the stability during storage and centrifugation, especially at 60 kV 60 s. Overall, sterilization of coconut milk by ACP at 60 kV 60 s was the most ideal. This study can provide theoretical guidance for the application of ACP in liquid food.

Preharvest and postharvest techniques that optimize the shelf life of fresh basil (Ocimum basilicum L.): a review

Basil (Ocimum basilicum L.) is a popular specialty crop known for its use as a culinary herb and medicinal plant around the world. However, its profitability and availability are limited by a short postharvest shelf life due to poor handling, cold sensitivity and microbial contamination. Here, we comprehensively review the research on pre- and postharvest techniques that extend the shelf life of basil to serve as a practical tool for growers, distributors, retailers and scientists. Modifications to postharvest storage conditions, pre- and postharvest treatments, harvest time and preharvest production methods have been found to directly impact the quality of basil and its shelf life. The most effective strategies for extending the shelf life and improving the quality of basil are discussed and promising strategies that research and industry employ are identified.

Fresh Basil Infusion: Effect of Sous-Vide Heat Treatment on Their Volatile Composition Profile, Sensory Profile, and Color

Herbs, including basil, are used to enhance the flavor of food products around the world. Its potential is influenced by the quality of fresh herbs and processing practices, wherein conditions of heat treatment play an important role. The aim of the research was to determine the effect of sous-vide heat treatment on the volatile compounds profile, sensory quality, and color of basil infusions. The material used for research was aqueous basil infusion prepared conventionally at 100 °C, and using the sous-vide method (65, 75, and 85 °C). The composition of volatile compounds was identified by GC/MS analysis, the sensory profile was assessed using a group of trained panelists, while the color was instrumentally assessed in the CIE Lab system. No significant differences were found in the intensity of the taste and aroma of basil infusions at different temperatures. Seventy headspace volatile compounds were identified in the analyzed samples, ten of which exceeded 2% of relative area percentage. The most abundant compounds were eucalyptol (27.1%), trans-ocimene (11.0%), β-linalool (9.2%), and β-myrcene (6.7%). Most of the identified compounds belonged to the terpenes and alcohols groups. Our findings show that the conventional herbal infusion was more like a sous-vide infusion prepared at the lowest temperature SV65, while SV75 and SV85 were similar to each other but different from the conventional. However, a smaller number of volatile compounds in the samples heated at higher temperatures of sous-vide were identified. The sous-vide samples showed a higher content of alkanes. The sous-vide method (p ≤ 0.05) resulted in darker, less green, and less yellow basil leaves than fresh and traditionally steeped ones. Long heat treatment under vacuum at higher temperatures causes a pronounced change in the aroma composition.

Characterization of Basil Volatile Fraction and Study of Its Agronomic Variation by ASCA

Basil is a plant known worldwide for its culinary and health attributes. It counts more than a hundred and fifty species and many more chemo-types due to its easy cross-breeds. Each species and each chemo-type have a typical aroma pattern and selecting the proper one is crucial for the food industry. Twelve basil varieties have been studied over three years (2018–2020), as have four different cuts. To characterize the aroma profile, nine typical basil flavour molecules have been selected using a gas chromatography–mass spectrometry coupled with an olfactometer (GC–MS/O). The concentrations of the nine selected molecules were measured by an ultra-fast CG e-nose and Principal Component Analysis (PCA) was applied to detect possible differences among the samples. The PCA results highlighted differences between harvesting years, mainly for 2018, whereas no observable clusters were found concerning varieties and cuts, probably due to the combined effects of the investigated factors. For this reason, the ANOVA Simultaneous Component Analysis (ASCA) methodology was applied on a balanced a posteriori designed dataset. All the considered factors and interactions were statistically significant (p < 0.05) in explaining differences between the basil aroma profiles, with more relevant effects of variety and year.

Metabolic Insights into the Anion-Anion Antagonism in Sweet Basil: Effects of Different Nitrate/Chloride Ratios in the Nutrient Solution

Sweet basil (Ocimum basilicum L.) is a highly versatile and globally popular culinary herb, and a rich source of aromatic and bioactive compounds. Particularly for leafy vegetables, nutrient management allows a more efficient and sustainable improvement of crop yield and quality. In this work, we investigated the effects of balanced modulation of the concentration of two antagonist anions (nitrate and chlorine) in basil. Specifically, we evaluated the changes in yield and leaf metabolic profiles in response to four different NO3-:Cl- ratios in two consecutive harvests, using a full factorial design. Our work indicated that the variation of the nitrate-chloride ratio exerts a large effect on both metabolomic profile and yield in basil, which cannot be fully explained only by an anion-anion antagonist outcome. The metabolomic reprogramming involved different biochemical classes of compounds, with distinctive traits as a function of the different nutrient ratios. Such changes involved not only a response to nutrients availability, but also to redox imbalance and oxidative stress. A network of signaling compounds, including NO and phytohormones, underlined the modeling of metabolomic signatures. Our work highlighted the potential and the magnitude of the effect of nutrient solution management in basil and provided an advancement towards understanding the metabolic response to anion antagonism in plants.

Aromatic Profiles of Essential Oils from Five Commonly Used Thai Basils

The research objectives of this study are to analyse the volatile compositions of different basil types available in Thai markets and to descriptively determine their aromatic qualities. Essential oils were hydro-distillated from fresh leaves of two Holy basil (Ocimum sanctum) varieties namely, white and red and other basil species, including Tree basil (O. gratissimum), Thai basil (O. basilicum var. thyrsiflorum), and Lemon basil (O. citriodorum). Oil physiochemical characteristics and volatile chromatograms from Gas Chromatography⁻Mass Spectrometry (GC-MS) were used to qualitatively and quantitatively describe the chemical compositions. Estragole, eugenol, and methyl eugenol were among the major volatiles found in the essential oils of these basil types. Classification by Principal Component Analysis (PCA) advised that these Ocimum spp. samples are grouped based on either the distinctive anise, citrus aroma (estragole, geranial and neral), or spice-like aroma (methyl eugenol, β-caryophyllene, and α-cubebene). The essential oils were also used for descriptive sensorial determination by five semi-trained panellists, using the following developed terms: anise, citrus, herb, spice, sweet, and woody. The panellists were able to differentiate essential oils of white Holy basil from red Holy basil based on the intensity of the anisic attribute, while the anise and citrus scents were detected as dominant in the Lemon basil, Tree basil, and Thai basil essential oils. The overall benefit from this research was the elucidation of aromatic qualities from Thai common Ocimum species in order to assess their potential as the raw materials for new food products.