Steviol glycosides (SGs) are natural sweeteners derived from stevia leaves, which have various applications in food and beverage products. The extraction efficiency of SGs depends on several factors, such as solvent type, solid to solvent ratio, centrifugal force, and temperature. This study aimed to compare the effects of different solvents (ethanol and water) and leaf moisture (dry and fresh) on the extraction efficiency of major steviol glycosides (SGs) of rebaudioside A (Reb A), stevioside (ST), and rebaudioside C (Reb C) in stevia (var. Levent 93) plant. A Box–Behnken design was used to optimise the extraction parameters for each extraction type. The results showed that ethanol was a more effective solvent than water, however, aqueous extraction was more environmentally friendly and low-cost, and could also yield high concentrations of SGs when fresh leaves were used. The major SGs had similar concentrations in ethanolic extraction, but Reb A was twice as high as ST in aqueous extraction. Reb C was influenced by the solid to solvent ratio in both extraction types, but more so in water extraction. Temperature had a positive effect on ST and Reb C in water extraction of fresh leaves, but not in water extraction of dry leaves or ethanolic extraction. The results of this study contribute to the optimisation of SGs extraction from stevia leaves and provide insights for future research on the effects of different solvents and extraction parameters on the quality and purity of SGs.

The objective of this study was to investigate the sensory characteristics of apricot drinks that were sweetened using stevia. The sensory examination of stevia powder revealed comparable levels of sweetness to sucrose, albeit with a more prominent perception of bitterness. When the substitution rate of stevia was 75%, the sweetness and overall preference parameters obtained the highest scores among the other apricot drink samples. Nevertheless, the utilization of pure stevia extract resulted in unfavorable flavor attributes (e.g., bitter, metallic, and acidic tastes, as well as chemical and synthetic odors). An increase in the concentration of stevia, combined with the reduction in sucrose content, resulted in a notable decrease in the energy content of the samples, while maintaining an acceptable sensory profile. The apricot drinks containing 75% stevia significantly decreased energy levels by 60% and received great ratings from the panelists. However, the utilization of pure stevia has led to the development of sour, pronounced, and metallic tastes, as well as disagreeable odors. On the other hand, the use of stevia at sucrose-substitution ratios of 25% or 50% showed positive taste characteristics.

Klimakterik meyvelerin hasattan sonra hızlı olgunlaşma süreçleri, hasat sonrası kalite yönetimi ve ticari ömrün uzatılması açısından zorluklar oluşturmaktadır. Bu çalışmada, etilen gazının olgunlaşma üzerindeki etkisini geciktiren 1-Metilsiklopropen (1-MCP) kullanımının, subtropikal koşullarda örtüaltında yetiştirilen ‘Sel-42’ ve ‘Tainung’ papaya çeşitlerinin soğukta muhafaza sırasında kalite parametreleri üzerindeki etkileri incelenmiştir. Bu amaçla, farklı dozlarda 1-MCP uygulamasının depolama süresinde meyve ağırlık kaybı, meyve eti sertliği, kabuk renk gelişimi ve kimyasal özellikleri üzerine etkileri araştırılmıştır. Araştırma bulguları, ‘Sel-42’ çeşidinde %25 olgunluk seviyesinde 1-MCP uygulamasının muhafaza süresini 28 güne ve ‘Tainung’ çeşidinde ise 31 güne kadar uzatabildiğini göstermiştir. Ayrıca 1-MCP uygulamalarının, meyve eti sertliğini ve renk dönüşümünü olumlu yönde etkilediği, ancak kimyasal özellikler üzerinde doğrudan bir etkisinin olmadığı tespit edilmiştirAraştırma sonuçları, 1-MCP uygulamasının ‘Sel-42’ ve ‘Tainung’ papaya çeşitlerinin muhafaza süresini ve meyve kalitesini iyileştirme konusunda önemli bir etkiye sahip olduğunu ve meyveye özgü muhafaza stratejilerinin geliştirilmesine katkı sağladığı sonucuna varılmıştır.

Enriching steviol glycosides derived from the stevia plant is an important step in producing stevia natural sweeteners. This study investigated the enrichment of Rebaudioside A and Stevioside compounds of aqueous and ethanol stevia extracts using cascade membrane filtration techniques. Accordingly, extracts from stevia leaves were processed using membrane filtration techniques such as ultrafiltration and nanofiltration. In particular, the 30 kDa ultrafiltration membrane was highly effective in enriching steviol glycosides. The highest concentrations of Rebaudioside A (21.47 g L-1) and Stevioside (19.97 g L-1) compounds were reached at the 30 kDa ultrafiltration retentate fraction in both aqueous and ethanolic extracts. However, it was found that the permeate fluxes and the extracts obtained after the nanofiltration process had very low concentrations of these compounds. The findings highlight the importance of membrane selection in effectively enriching steviol glycosides.