Quality of fresh and stored foam mat dried Mandarin powder

Foam mat drying is a lucrative process of mandarin (kinnow) pulp preservation in the form of powder. Foam mat drying of mandarin pulp experiments were carried out at 65, 75 and 85 °C drying air temperatures using carboxy methyl cellulose, milk and egg white as foaming agents at different concentrations levels to get dried mandarin powder. Quality of the reconstituted dried Mandarin pulp‐powder was evaluated for 6 month storage studies at an interval of 2 months for total sugars (%), ascorbic acid (mg 100 mL^?1), total acid (%), pH and microbial load (fungal and bacterial) using standard procedures. It was observed that total sugars, ascorbic acid and total acid were decreased whereas pH was slightly higher than the fresh pulp. There was minor bacterial growth noticed in all the treatments, which is within the permissible limit, furthermore no fungal growth was noticed during storage period.     

Effect of intermittent microwave convective drying on physicochemical properties of dragon fruit

Food Science and Biotechnology - The study was carried out to investigate the effect of Intermittent microwave convective drying (IMCD) on the overall quality of dried dragon fruit in terms of...     

微波泡沫干燥条件对树莓果浆干燥特性影响

为了研究微波泡沫干燥树莓果浆传热传质特性,以树莓为原料,采用中心组合实验设计方法,研究干燥条件对物料温度、含水率以及介电特性的影响规律,分析微波泡沫干燥过程中传热传质过程。结果表明:微波泡沫干燥树莓果浆过程中,干燥初期,介电常数与介电损耗因子均增大,使得物料吸收的微波能增大,果浆温度由室温上升至70℃,含水率无明显变化;干燥中期,介电常数与介电损耗因子先增大后减小,因此物料吸收的微波能呈先增大后减小趋势,果浆含水率由90%降至40%,温度变化不明显;干燥后期,介电常数与介电损耗因子均减小,物料吸收的微波能减少,果浆含水率缓慢降至15%左右,温度继续升高。微波泡沫干燥方法可有效提高高粘度果浆的干燥速度。      

陈酿方式对无花果果酒理化特性及体外抗氧化性的影响

选择红外催陈、冷热交替、自然陈酿3种陈酿方式,探讨陈酿对无花果果酒理化特性和体外抗氧化性的影响。对陈酿后果酒的总酸、总酯、透光率、感官品质、总酚、多糖、总黄酮和体外抗氧化性进行分析。结果表明:陈酿后果酒总酯含量均显著高于新酒,总酚、多糖、总黄酮和体外抗氧化性能均有不同程度的下降。红外催陈15 h后,果酒的理化指标为:总酸4.9 g/L、总酯2.25 g/L、透光率81.6%、总酚1.61 g/L、多糖1.35 g/L、总黄酮0.63 g/L、DPPH自由基清除率为5.53 mg(抗坏血酸)/L、超氧阴离子自由基清除率为10.39 mg(抗坏血酸)/L、总还原能力38.95 mg(抗坏血酸)/L,感官评分85.53分,在达到无花果果酒后熟效果且增加口感的同时,能更好地保留无花果果酒的体外抗氧化性能,综合品质较好。     

Spray drying of red (Hylocereus polyrhizus) and white (Hylocereus undatus) dragon fruit juices: physicochemical and antioxidant properties of the powder

This study aims to investigate physical stability and antioxidant properties of spray‐dried red (Hylocereus polyrhizus) and white (Hylocereus undatus) dragon fruit powder upon storage at various relative humidity (RH). Inlet air temperatures of 120 °C (red dragon fruit) and 110 °C (white dragon fruit) as well as maltodextrin concentration of 30% (w/v) were selected as the spray drying conditions as powder was obtained at these minimum conditions. The powder was ranging from 3 to 7 μm in particle size with spherical morphology. The powder had lower antioxidant content and antioxidant activities compared with the control before spray drying. Storage of powder at 43%, 54% or 75% RH at 25 °C for 25 days resulted in structural changes correlating to the depression of glass transition temperatures (T_g) to below storage temperature. At 33% RH, no visible structural changes were observed. Antioxidant properties of the powder remained unchanged after 25 days' storage at the studied RHs.     

Effects of spray drying conditions on the physicochemical and antioxidant properties of the Gac (Momordica cochinchinensis) fruit aril powder

Gac fruit aril has an attractive orange red colour and very high level of carotenoids, giving it exceptional antioxidant properties. However, spray drying of this material has not been successful and malto dextrin is considered as a suitable drying aid to preserve its colour and antioxidant properties. This paper reports the effects of inlet drying air temperature (120, 140, 160, 180 and 200 °C) and maltodextrin addition (10%, 20% and 30%) on the physicochemical and antioxidant properties of the Gac aril powder. Moisture content and bulk density, colour characteristics, total carotenoid content (TCC), encapsulation efficiency and total antioxidant activity (TAA) were significantly affected by maltodextrin concentration and the inlet air temperatures. However, pH, a_w and water solubility index were not significantly influenced by the spray drying conditions. Overall, a good quality Gac powder in terms of colour, TCC and TAA can be produced by spray-drying at inlet temperature of 120 °C and adding maltodextrin concentration at 10% w/v.     

Effects of different drying methods on the physicochemical property and edible quality of fermented Pyracantha fortuneana fruit powder

In this study, hot air drying (HAD), hot air-/microwave-assisted vacuum drying (HAMAVD) and hot air-assisted microwave drying (HAAMD) were applied to lactic acid-fermented Pyracantha fortuneana fruit (PFF). Influences of different drying methods on fluidity and dispersion, microstructure, hygroscopicity, rehydration, colour change, sourness and energy consumption were investigated. Results showed that HAAMD had the best overall performance on the quality of the PFF powder. HAAMD PFF powder had higher expansion force (1.65 mL g⁻¹) and water-holding capacity (2.68 g g⁻¹), lower degree of compression (9.09%) and energy consumption, smaller colour change and better taste. Organic acids (mainly malic acids) of all drying powders decreased, but HAAMD and HAMAVD could better improve the acidity characteristics of PFF powders, which may be related to the drying time and the temperature change processes. Consequently, this study can provide references for the utilisation of fresh PFF, the design and commercialisation of PFF-related products.