EMULSION COATING TO EXTEND POSTHARVEST LIFE OF MANGO (MANGIFERA INDICA CV. MANILA)

A coating emulsion was prepared using maltodextrins, carboxymethylcellulose, propileneglycol and a mixture of s orbit an fatty acid esters with an HLB of 6. The emulsion was sprayed on fully mature, unripened manila mangoes, which were the stored at 15 and 25C and 80–85% R.H. At 25C it was observed that rate CO² production increased and lost in control fruits after 12 days of storage. Coated mangoes kept their rate CO² production and suffered only 8% weight loss after 21 days of storage. After storage, the coating was washed out and fruits were allowed to ripen naturally, which occurred in 3–4 days. The results obtained from this study indicate that application of the hydrophobic coating extended the postharvest storage of mangoes for at least 20 days more than uncoated fruits.     

Cellular/dendritic transition,dendritic growth and microhardness in directionally solidified monophasic Sn-2%Sb alloy

Horizontal directional solidification experiments were carried out with a monophasic Sn-2%Sb (mass fraction) alloy to analyze the influence of solidification thermal parameters on the morphology and length scale of the microstructure. Continuous temperature measurements were made during solidification at different positions along the length of the casting and these temperature data were used to determine solidification thermal parameters, including the growth rate (V_L) and the cooling rate (T_R). High cooling rate cells and dendrites are shown to characterize the microstructure in different regions of the casting, with a reverse dendrite-to-cell transition occurring for T_R>5.0 K/s. Cellular (l_c) and primary dendrite arm spacings (l₁) are determined along the length of the directionally-solidified casting. Experimental growth laws relating l_c and l₁ to V_L and T_R are proposed, and a comparative analysis with results from a vertical upward directional solidification experiment is carried out. The influence of morphology and length scale of the microstructure on microhardness is also analyzed.     

Local multi-valued logics in modular expert systems

Abstract

Abstract. In this paper we describe an approach to the problem of dealing with uncertainty by means of finite multi-valued logics in modular expert systems, and the results obtained. The modularity of the systems allows us to address two main characteristics of human problem-solving: the adaptation of general knowledge to particular problems and the dependency of the management of uncertainty on the different subtasks being implemented in the modules of the system, i.e. different modules can have different local multiple-valued logics as part of their local deductive mechanisms. Although the results obtained are general, we use, throughout the paper, examples of a medical expert system that has been designed using a modular language called MILORD-II, that implements them showing the practical interest of the theoretical concepts involved.     

A RESEARCH NOTE: SENSORY QUALITY CHANGES OF HIGH MOISTURE PINEAPPLE BITS DURING STORAGE

Minimally processed high moisture pineapple bits prepared in sucrose syrups, in order to decrease water activity to 0.92, 0.95 and 0.97, were stored at 30, 35 and 40C and evaluated by selected and trained sensory panelists using the Karlsrühe Quality Test. Color, flavor and texture changes were significantly lower for the 0.92 a_w product stored at 30C. It can be predicted by shelf‐life estimation that this product will maintain a satisfactory sensorial and microbiological quality for up to 50 days.     

定向凝固单相Sn-2%Sb合金的胞/枝晶转变、枝晶生长和显微硬度（英文）

采用单相Sn-2%Sb(质量分数)合金进行水平定向凝固实验,分析凝固热参数对显微组织形貌和长度尺度的影响。在凝固过程中,对沿铸坯长度方向的不同部位进行连续温度测量,用这些温度数据来确定凝固热参数,包括生长速率(V_L)和冷却速率(T_R)。高冷却速率的胞晶和枝晶可以表征铸件不同区域的显微组织,当T_R5.0 K/s时发生枝晶向胞晶的可逆转变。沿定向凝固铸造的长度方向确定胞晶尺寸(λ_c)和一次枝晶间距(λ_1),提出关于λ_c和λ_1与V_L和T_R的实验生长规律,并与垂直向上定向凝固实验结果进行对比分析,并分析显微组织形貌和长度尺度对显微硬度的影响。     

CAN WE PREDICT PEELING PERFORMANCE OF PROCESSING TOMATOES?

Tomato processors are increasingly interested in being able to predict whether tomatoes will peel well, and therefore, yield high‐value processed tomatoes. We describe two statistical models for peeling applied to multiple years of data. One model is appropriate for perfect or defect‐free tomatoes, and the second model is valid for the normal population of tomatoes obtained following mechanical harvesting. The ability to peel perfect tomatoes was significantly affected by exposure of tomatoes to temperatures greater than 100F, by fruit weight and by pericarp wall thickness. The peelability of a normal population of tomatoes was influenced by tomato weight and width as well as degree‐days and exposure to temperatures greater than 90F. Thickness of the pericarp walls and red layer positively affected the peelability of normal tomatoes. The ability to predict tomato peelability using statistical models may improve the quality of processed tomatoes and may result in more efficient commercial peeling operations.     

Drying of bananas using microwave and air ovens

Drying tests for ripe and green banana (Musa cv. Giant Cavendish AAA) slices and for a foam made from ripe banana puree were performed in a household microwave oven and in a laboratory forced draft warm air oven. Weight change of the banana slices as a function of time in both ovens, and temperature and relative humidity (RH) of air leaving the microwave oven were recorded. Drying rates were calculated and the data fitted to a variable diffusion model. Drying time in the microwave oven was seventeen to twenty times less than in the forced draft oven. The drying energy efficiency in the microwave oven was about 30%.     

CONCENTRATION of ORANGE JUICE BY REVERSE OSMOSIS

Orange juice was concentrated by RO up to 50% hydraulic recovery with a polyamide membrane. Permeate fluxes and solute recoveries were determined at transmembrane pressures of 6.21 and 4.14 MPa. Pectinase treatment was required to prevent fouling and to allow Cleaning in Place procedures. Enzymatic treatment did not affect permeate flux or solute recoveries. Overall recovery of sugars, organic acids, and flavor-volatile components was approximately 93%.     

Surface active molecules: preparation and properties of long chain nα-acyl-l-α-amino-ω-guanidine alkyl acid derivatives

A new route for the synthesis of long chain N ^α-acyl- l -α-amino-ω-guamdine alkyl acid derivatives, with cationic or amphoteric character has been established. The general formula of these compounds is shown below.
A physico-chemical and antimicrobial study of these products as a function of the alkyl ester or sodium salt (R), the straight chain length of the fatty acid residue ( x ) and the number of carbons between the ω-guanidine and ω -carboxyl group ( n ) has been investigated.
The water solubility, surface tension, critical micelle concentration (c.m.c.) and minimum inhibitory concentration (MIC) against Gram-positive and Gram-negative bacteria (including Pseudomonas) has been determined.
Dicyclohexylcarbodiimide has been used to condense fatty acids and α -amino-ω-guanidine alkyl acids. In these conditions protection of the ω-guanidine group is not necessary. The main characteristic of this synthetic procedure is the use of very mild experimental conditions (temperature, pH) to form the amide linkage which leads to pure optical compounds in high yield in the absence of electrolytes.
The results show that some structural modifications, particularly the protection of the carboxyl group, promote variations of the surfactant and antimicrobial properties. Only those molecules with the blocked carboxyl group (cationic molecules, where R = Me, Et or Pr) showed a good surfactant and antimicrobial activity. When the carboxyl group was unprotected (amphoteric molecules, where R = Na⁺) the resulting compounds were inactive.