{"title":"降糖对冻干番茄粉的玻璃化转变温度和吸附等温线的影响","authors":"Robert Thierry Malomar , Caroline Garcia , Béatrice Gleize , Vanessa Jury , Emilie Korbel , Francine Fayolle","doi":"10.1016/j.jfoodeng.2024.112137","DOIUrl":null,"url":null,"abstract":"<div><p>The objective of this work was to improve the drying of tomato juices after identifying the main parameters that are responsible for sticking during drying. Glass transition temperature (T<sub>g</sub>) which is one of the key parameter, depends on the juice composition, mainly sugar. In order to reduce sugar, centrifugation was applied to the juices. T<sub>g</sub> was determined by differential scanning calorimetry (DSC) for freeze-dried tomato juice and tomato pellet conditioned at various water activity (a<sub>w</sub>) (0.1–0.5). The glass transition curve showed that T<sub>g</sub> decreased with increasing of the moisture. Comparison of powders obtained by juice and pellet from centrifugation shows that the T<sub>g</sub> of freeze-dried pellets is higher than that of juice at equal a<sub>w</sub> values. Adsorption isotherms of freeze-dried tomato juice and pellet were determined at 25 °C and a relative humidity (RH) of 0–98% using a dynamic technique. The data obtained were fitted to GAB model that best fitted the experimental data. The equilibrium moisture content (X) value of the freeze-dried pellets are lower and had the same value of 8% dry mass. X is lower because the pellet powders are less hygroscopic than tomato juice powders because of the reduction of soluble compounds by centrifugation, notably sugars. Reducing the product sugar content by centrifugation enables to raise T<sub>g</sub> without using carriers and obtain less hygroscopic powders, which is advantageous for product storage.</p></div>","PeriodicalId":359,"journal":{"name":"Journal of Food Engineering","volume":null,"pages":null},"PeriodicalIF":5.3000,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0260877424002036/pdfft?md5=d9c5f8128be7938f1180f1e44f5e3553&pid=1-s2.0-S0260877424002036-main.pdf","citationCount":"0","resultStr":"{\"title\":\"Impact of sugar reduction on the glass transition temperature and sorption isotherm of freeze-dried tomato powder\",\"authors\":\"Robert Thierry Malomar , Caroline Garcia , Béatrice Gleize , Vanessa Jury , Emilie Korbel , Francine Fayolle\",\"doi\":\"10.1016/j.jfoodeng.2024.112137\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>The objective of this work was to improve the drying of tomato juices after identifying the main parameters that are responsible for sticking during drying. Glass transition temperature (T<sub>g</sub>) which is one of the key parameter, depends on the juice composition, mainly sugar. In order to reduce sugar, centrifugation was applied to the juices. T<sub>g</sub> was determined by differential scanning calorimetry (DSC) for freeze-dried tomato juice and tomato pellet conditioned at various water activity (a<sub>w</sub>) (0.1–0.5). The glass transition curve showed that T<sub>g</sub> decreased with increasing of the moisture. Comparison of powders obtained by juice and pellet from centrifugation shows that the T<sub>g</sub> of freeze-dried pellets is higher than that of juice at equal a<sub>w</sub> values. Adsorption isotherms of freeze-dried tomato juice and pellet were determined at 25 °C and a relative humidity (RH) of 0–98% using a dynamic technique. The data obtained were fitted to GAB model that best fitted the experimental data. The equilibrium moisture content (X) value of the freeze-dried pellets are lower and had the same value of 8% dry mass. X is lower because the pellet powders are less hygroscopic than tomato juice powders because of the reduction of soluble compounds by centrifugation, notably sugars. 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引用次数: 0
摘要
这项工作的目的是在确定导致番茄汁在干燥过程中粘连的主要参数后,改进番茄汁的干燥。玻璃转化温度(Tg)是关键参数之一,它取决于果汁成分,主要是糖分。为了减少糖分,对果汁进行了离心处理。通过差示扫描量热法(DSC)测定了冻干番茄汁和番茄颗粒在不同水活度(aw)(0.1-0.5)条件下的玻璃化温度。玻璃化转变曲线显示,Tg 随水分的增加而降低。比较果汁和离心分离得到的颗粒粉末发现,在相同的 aw 值下,冻干颗粒的 Tg 要高于果汁。在 25 °C 和相对湿度(RH)为 0-98% 的条件下,使用动态技术测定了冻干番茄汁和颗粒的吸附等温线。所获得的数据被拟合到最适合实验数据的 GAB 模型中。冻干颗粒的平衡含水量(X)值较低,与 8%的干质量值相同。X 值较低的原因是,颗粒粉末的吸湿性比番茄汁粉末低,这是因为离心作用减少了可溶性化合物,特别是糖类。通过离心减少产品中的糖分含量,可以在不使用载体的情况下提高 Tg 值,并获得吸湿性较小的粉末,这对产品的储存非常有利。
Impact of sugar reduction on the glass transition temperature and sorption isotherm of freeze-dried tomato powder
The objective of this work was to improve the drying of tomato juices after identifying the main parameters that are responsible for sticking during drying. Glass transition temperature (Tg) which is one of the key parameter, depends on the juice composition, mainly sugar. In order to reduce sugar, centrifugation was applied to the juices. Tg was determined by differential scanning calorimetry (DSC) for freeze-dried tomato juice and tomato pellet conditioned at various water activity (aw) (0.1–0.5). The glass transition curve showed that Tg decreased with increasing of the moisture. Comparison of powders obtained by juice and pellet from centrifugation shows that the Tg of freeze-dried pellets is higher than that of juice at equal aw values. Adsorption isotherms of freeze-dried tomato juice and pellet were determined at 25 °C and a relative humidity (RH) of 0–98% using a dynamic technique. The data obtained were fitted to GAB model that best fitted the experimental data. The equilibrium moisture content (X) value of the freeze-dried pellets are lower and had the same value of 8% dry mass. X is lower because the pellet powders are less hygroscopic than tomato juice powders because of the reduction of soluble compounds by centrifugation, notably sugars. Reducing the product sugar content by centrifugation enables to raise Tg without using carriers and obtain less hygroscopic powders, which is advantageous for product storage.
期刊介绍:
The journal publishes original research and review papers on any subject at the interface between food and engineering, particularly those of relevance to industry, including:
Engineering properties of foods, food physics and physical chemistry; processing, measurement, control, packaging, storage and distribution; engineering aspects of the design and production of novel foods and of food service and catering; design and operation of food processes, plant and equipment; economics of food engineering, including the economics of alternative processes.
Accounts of food engineering achievements are of particular value.