Apple rings as a model for fruit drying behavior: Effects of surfactant and reduced osmolality reveal biological mechanisms

Drying behavior at 60°C was studied in uniform rings of apple fruit parenchyma after vacuum infiltration of fluids with different osmolality and surface tension. All infiltrations gave a halved final porosity. Both reduced surface tension and reduced osmolality caused tissue destruction shown as darker visual color. Addition of surfactant resulted in a high drying rate on a surface area basis corresponding to 15% more water lost after 2 h. The results indicate that biological mechanisms related to function and structure of living tissue are important for drying behavior. The apple ring model is suitable for further studies of biological and other types of drying behavior in relation to the tissue organization

Exergy Analysis of Food Drying Processes

It is well known that micro-level system parameters may have some great impact on macro-level energy aspects, the environment, and sustainability. Of course, if one wants to approach these thermodynamically, there are two ways: energy analysis through the first law of thermodynamics and exergy analysis through the second law of thermodynamics. Exergy analysis is an essential tool to expose the impacts of a power generating device on exergy-based sustainability; sustainability is necessary to overcome current ecological, economic, and developmental problems (Dincer and Rosen, 2005). In this regard, some new exergy-based sustainability parameters for a PEM fuel cell have been developed and studied parametrically to investigate how they will help measure the level of environmental impact and sustainable development (Midilli and Dincer, 2009). These types of parameters may also be applied to other energy-related systems.TÜBİTAK Project No. 106M48

Effect of seed roasting on oxidative stability and antioxidant content of hemp seed oil

In this study, some chemical components of hemp seed, which widely consumed as snack food in Middle East were determined. The effects of different roasting temperatures (140, 160 and 180 °C) and times (0–60 min) on the oxidative stability and antioxidant content of hemp seed oil were investigated. Hemp seed oil contained high levels of linoleic acid (54.85%), α-linolenic acid (18.13%) and γ-tocopherol (707.47 mg/kg oil). While tocopherol isomers decreased with increasing roasting time and temperature, total phenolic content and antioxidant activity showed increasing trend. The peroxide and p-anisidine values of roasted samples varied from 1.33 to 3.09 meq O(2) /kg oil and 1.65 to 43.27, respectively. The peroxide and p-anisidine values of samples were simultaneously generated at the early stage of roasting. Kinetic evaluation of data showed that peroxides act as limiting factor in autocatalytic oxidation reactions. The order and rate constant regarding peroxide value were similar with those of p-anisidine value. The effects of roasting temperature and time on the oxidation parameters and antioxidant contents of samples were significant (p < 0.05). Based on peroxide and p-anisidine values, roasting at 140–160 °C for 35 min or at 180 °C for 15 min are recommended to provide good quality roasted hemp seed

Oxidative Stability of Commodity Fats and Oils: Modeling Based on Fatty Acid Composition

Although fatty acid (FA) composition is known to be of fundamental importance to oxidative stability in lipids, consistent quantifications of the magnitude of this association have proved elusive. The objective of this study was to quantify the relationship between FA composition and stability on a large scale within comparable lipid systems, with the numerical effects of individual outcome factors (e.g. output of a singular assay, oxidative products after a brief period of time, etc.) attenuated by incorporation into a comprehensive summation of stability. The stability of 50 plant-based oils and fats was modeled according to FA composition, utilizing a quantification of stability that encompassed the complete oxidation curves of four distinct classical assays (two 1° and two 2° oxidation assessments) throughout 2 months of accelerated storage (60 °C). In our models, the concentrations of monounsaturated FA (MUFA), diunsaturated FA (DiUFA), and triunsaturated FA (TriUFA) together demonstrated a very strong correlation with our consolidated measure of stability (r 2 = 0.915; greater than observed with our assessments by individual assays). The resultant model also indicated the relative effect upon magnitude of oxidation of MUFA:DiUFA:TriUFA to be approximately 1:3:12 - substantially greater than the 1:2:3 ratio of their relative unsaturation

Osmotic Dehydration of Pineapple with Impregnation of Sucrose, Calcium, and Ascorbic Acid

Mass transfer was evaluated during osmotic dehydration of pineapple in solutions with until four components aiming to investigate the solutes concentration influence on impregnation. In the first step, the experimental trials for optimization of solution concentration were based on 23 factorial design. In the second step, effective diffusion coefficients were determined. Equations representing the influence of the concentration of sucrose, calcium lactate, and ascorbic acid in osmotic solutions on water loss and gains of sucrose, calcium, and vitamin C were found. Results showed that both calcium lactate and sucrose concentration affected calcium and sucrose gain. On the other hand, only vitamin C gain was significantly affected by the ascorbic acid concentration in the studied concentration range. However, when comparing diffusivities in pineapple immersed in sucrose solutions, with and without calcium lactate, with and without ascorbic acid, it was possible to verify that diffusivities of water, sugar, and calcium increased in presence of ascorbic acid in solution. Calcium in solution diminished the water and sucrose diffusivities. High calcium and vitamin C contents were obtained in 1 h immersion in the solutions studied. © 2013 Springer Science+Business Media New York.Department of Food Engineering and Technology, Institute of Biosciences, Language and Physical Scien UNESP-São Paulo State University Rua Cristóvão, Colombo 2265, São José do Rio Preto, 15054-000Department of Food Engineering and Technology, Institute of Biosciences, Language and Physical Scien UNESP-São Paulo State University Rua Cristóvão, Colombo 2265, São José do Rio Preto, 15054-00