This study aimed to comparatively optimize and evaluate the quality characteristics of Washington Navel orange slices using vacuum microwave drying (VMD) and conventional hot air drying (HAD) systems. Response Surface Methodology based on the Box–Behnken design was applied to both systems. For the models developed in the VMD system, the coefficient of determination (R²) was found to be in the range of 0.96–0.97, and the optimum conditions were determined as 4 kW power, 60 °C temperature, and 2 mm slice thickness. For HAD, the optimum conditions were determined as 78 °C temperature, 1.57 m/s air velocity, of 2.3 mm slice thickness. VMD showed superior performance compared to hot air drying in terms of total phenolic preservation, retention of bioactive compounds, and rehydration capacity. Hydroxymethylfurfural (HMF) formation was higher during hot-air drying. The effective moisture diffusivity (D_eff) was significantly higher in VMD (8.38 × 10⁻¹⁰ m²/s) than in HAD (1.49 × 10⁻¹⁰ m²/s), indicating enhanced internal moisture transport under vacuum microwave conditions. The results revealed that VMD is an efficient technology for producing high-quality dried citrus products with improved bioactive retention and reduced processing time.

This study was conducted to determine some physicochemical characteristics and bioactive compounds of Turkish pine nut cold pressed oil. The moisture content, total protein amount and crude oil yield of the pine nut were 3.18%, 31.46% and 35.58% respectively. The fatty acid profile, tocopherol and sterol contents of this oil were characterized. Linoleic acid (46.39%) was found to be the predominant fatty acid followed by palmitic (6.3%), stearic (3.5%), gadoleic (0.81%), linolenic (0.58%), eicosadienoic (0.49%), oleic (37.73%), behenic (0.13%), palmitoleic (0.1%), margaric (0.08%), myristic (0.06%) and heptadecenoic acid (0.05%). Regarding tocopherol composition, α-tocopherol (174.48 µg/g), γ-tocopherol (485.92 µg/g) and α-tocotrienol (2004.65 µg/g) were major ingredients in the pine nut oil. Regarding sterol composition, pine nut oil was determined to have remarkably high content of β-sitosterol (76.15%). The other sterols present in the oil were campesterol (15.60%), sitostanol (6.46%), D-5,24-stigmastadienol (1.43%) and ergosterol (0.36%). The most abundant triacylglycerol (TAG) was LLL (trilinolein) (11.5867%) followed by OLnL (Oleolinolenolinolein) (0.7302%), PLnL (Palmitolinolenolinolein) (0.1422%) and PoLL (Palmitoleodilinolein) (0.0826%).

Nadir şekerler, alternatif tatlandırıcılar olarak sağlık açısından oldukça faydalı olmaları ve endüstriyel açıdan ekonomik değerlerinin yüksek olmaları sebebiyle büyük ilgi görmektedir. Nadir şekerlerin doğada çok sınırlı miktarlarda bulunması, bitkilerden elde edilen yaygın şekerlerin enzimatik, kimyasal veya diğer yollarla nadir şekerlere dönüştürülmesine yönelik çalışmaları teşvik etmiştir. Nadir şekerler arasında çok önemli bir yere sahip olan D-alluloz, sakkaroza çok yakın bir tatlılığa sahip olması ve düşük kalorisi ile dikkat çeken bir şekerdir. Kandaki glikoz seviyesini düşürme, insülin direncini iyileştirme, vücuttaki yağ birikimini azaltma ve ateş düşürme gibi birçok biyolojik fonksiyonu düzenleme özelliğine sahip olması, bunun yanı sıra, yüksek çözünürlüğe ve gıda dokusu üzerinde olumlu etkilere sahip olması, bu şekerin gıda işlemede kullanımını daha cazip hale getirmektedir. D-alluloz "sindirilemeyen karbonhidrat" olarak bilinmektedir. Birçok meyve ve içecekte ve bazı tahıl ürünlerinde doğal olarak bulunmaktadır. Günümüzde D-alluloz, bitkiden ekstraksiyon, kimyasal sentez, enzimatik dönüşüm gibi birçok yöntemle üretilebilmekte ve bazı gıda maddelerinin üretiminde güvenle kullanılabilmektedir. Bu derlemede, günümüze kadar geliştirilmiş ve uygulanmış olan D-alluloz üretim yöntemleri açıklanmış, bu yöntemler arasındaki farklar ve birbirlerine göre avantajları ve dezavantajları tartışılmıştır.

Xylitol is a leading low-calorie sugar alcohol worldwide. Industrial production efficiency has become crucial given the increasing global demand. The catalytic hydrogenation of xylose to produce xylitol is a leading method. In this study, xylitol production using a Raney nickel catalyst was optimized in a pressurized batch reactor. The catalyst amount, xylose concentration, hydrogen pressure, and temperature were used as the process variables, and the maximum yield (%) was determined. The experimental design, created using a central composite design (CCD), was optimized using Response Surface Methodology (RSM), and the obtained values were evaluated using ANOVA. The linear regression model was found to be statistically significant. The linear model indicated that temperature had no effect on the model. The optimal conditions determined by the RSM were 40 g of catalyst, 25% xylose, and 60 bar at 400 rpm stirring. The yield was 86.61%, which is quite close to the predicted value of 87.2557%, demonstrating the accuracy of the model. The product was analyzed using HPLC, XRD, DSC, TGA, and ICP-MS to confirm product quality. Under these optimized chemical conditions, increasing the stirring speed to 800 rpm as a post-optimization step led to a further increase in yield up to 98.01%, indicating the presence of mass transfer limitations at lower mixing intensities.