Effects of Microwave Blanching Treatment on POD Activity and Crispness in Capsicum frutescens L.

[Objective] To study the effects of microwave blanching treatment on POD activity and crispness in Capsicum frutescens L., and to compare the effects of microwave blanching method, normal blanching method, boiling water blanching and steam blanching. [Methods] In order to obtain the optimal condition for microwave blanching, response surface methodology was used to construct a quadratic regression model describing the effects of microwave power, microwave time and calcium lactate concentration on the POD activity in C. frutescens. [Results] The optimal technology was obtained based on central composite design： 525 W microwave power, 64.5 s microwave time, and 0.08% calcium lactate concentration. Under this condition, POD enzyme activity of C. frutescens was desactivated and crispness of C. frutescens was 68.77 N. [Conclusions] This research would provide references for the crispness protection and enzyme deactivation of C. frutescens.

Experimental Investigation on Simultaneous Dry Blanching and Drying of Mushroom Slices Using Microwave Enhanced Hot Air Heating System

The study evaluated the feasibility of using microwave enhanced hot air heating system for simultaneous dry blanching and dehydration of mushroom slices. The technology involves application of microwave energy at the beginning of dehydration process to inactivate enzymes as well as to remove a certain amount of moisture at the same time and then followed by hot air drying to complete the process. The study investigated effects of different processing parameters, i.e., microwave power level and exposure time on dehydration and quality characteristics of mushroom slices. Mushroom slices were pretreated with different microwave power levels of 240, 360 and 480 W for 1, 3 and 5 min before the hot air-drying. The optimum range of the microwave power level and pretreatment time was found to be 360 W, 3 min and 360 W, 1 min in obtaining the maximum and minimum levels of response parameters.

Optimization of Blanching Time, Sodium Metabisulphite （Na2S205） Concentration and Processing Time on Vitamin C Content, Microbial Quality and Sensory Characteristics during Canning of Green Pepper （Capsicum sinensis） Using Response Surface Methodology

Response surface methodology and central composite rotatable design （CCRD） for K = 3 were used to investigate the combined effect of blanching time （0-1 min）, processing time （10-30 min） and sodium metabisulphite （Na2S205） salt concentration （0%-2%） on vitamin C content, hardness （texture）, microbial count and color intensity of green pepper （Capsicum sinensis） during canning. Blanching, processing time and sodium metabisulphite （Na2S205） salt concentration all had variable effects on the vitamin C, microbial quality and sensory characteristics of the canned green peppers. Significant （P 〈 0.05） interactions were noted between all the factors with high regression coefficients （78.7%-97.0%）. Increasing processing time caused significant decreases in vitamin C and microbial load of the product. However, salt concentration had only marginal and insignificant effect on the vitamin C content of the canned product. Sensory evaluation on the product showed that both the pre-processing conditions and of blanching and salt concentrations, and the processing time had varied effects on the color and hardness of the products. Hardness of the canned products generally decreased with increasing processing time and blanching time, while only minimal and insignificant effects were noted with blanching time. Increasing blanching time caused significant increasing retention of the dark green color of the peppers with only slight but insignificant increases noted with processing time, while increases in salt concentration consistently reduced the dark green color of the products. The optimum pre-processing and processing conditions that yielded products with high preference and consumer-acceptability were： blanching time of 0 min, processing time of 10 min and sodium metabisulphite concentration of 0.2%.

Recent developments and trends in thermal blanching-A comprehensive review

Thermal blanching is an essential operation for many fruits and vegetables processing.It not only contributes to the inactivation of polyphenol oxidase(PPO),peroxidase(POD),but also affects other quality attributes of products.Herein we review the current status of thermal blanching.Firstly,the purposes of blanching,which include inactivating enzymes,enhancing drying rate and product quality,removing pesticide residues and toxic constituents,expelling air in plant tissues,decreasing microbial load,are examined.Then,the reason to why indicators such as POD and PPO,ascorbic acid,color,and texture are frequently used to evaluate blanching process is summarized.After that,the principles,applications and limitations of current thermal blanching methods,which include conventional hot water blanching,steam blanching,microwave blanching,ohmic blanching,and infrared blanching are outlined.Finally,future trends are identified and discussed.

Innovative superheated steam impingement blanching(SSIB)enhances drying rate and quality attributes of line pepper

Blanching is an essential step before processing of agricultural products as it can inactivate enzymes that cause undesirable changes.In current work the effects of superheated steam impingement blanching(SSIB)time and temperature on drying characteristics and red pigments content of line pepper were investigated.Results showed that after a 3-min SSIB pretreatment at 110℃ the pepper epidermis covered with wax coat was damaged.In addition,the drying time was extensively decreased and the loss of red pigments of dried products was reduced.Results showed that the whole drying process took place in the falling rate period,which indicated that diffusion was the dominant physical mechanism governing moisture movement in the samples.Therefore,the second Fick’s law of diffusion was used to determine the effective moisture diffusivity(Deff)of line pepper,which increased from 1.193×10^-10 to 3.128×10^-10 m^2/s with increasing of the drying temperature and air velocity.The drying activation energy(Ea)of pretreated samples was 34.31 kJ/mol,which decreased by 3% compared with the non-pretreatment group.The findings of this work indicate that SSIB is very promising pretreatment technique as it not only enhances drying process but also improves bioactive substance preservation of red pepper.

Impact of blanching pretreatment on the drying rate and energy consumption during far-infrared drying of Paprika(Capsicum annuum L.)

We incorporated a superheated steam blanching pretreatment step into a paprika drying process and compared the far-infrared(FIR)drying rates,hardness of the sample surfaces,cell membrane stabilities,and energy consumption of blanched and non-blanched paprika.The average drying rate of blanched paprika samples during FIR drying was higher than that of non-blanched samples.The hardness and cell membrane stability of dried blanched samples were lower than those of non-blanched samples.We estimated that the softening of the sample surfaces and injury to the cell membranes caused the drying rate to increase.The total energy consumption of the FIR drying of paprika was reduced by approximately 30%by introducing the blanching pretreatment.These findings contribute to the development of environmentally friendly FIR drying techniques for paprika.

Comparative study of green peas using with blanching & without blanching techniques

This paper attempts to analyze the kinetics involved in the drying of green peas in‘with blanching’and‘without blanching’techniques.Blanching by hot water mixed with a solution of citric acid(0.1–0.2 mg/ml)at 70
C–100
C is the treatment provided to the samples of green peas.Experimental analysis shows that the moisture content in green peas of three different sizes is reduced at different temperatures and demonstrates the effect of the rate of drying of the moisture content.Under different diameters and temperatures,the parameters are analyzed using‘with blanching’and‘without blanching’techniques.It is observed that‘with blanching’process plays a significant role in the reduction of moisture content under different temperatures and diameters in a lesser time as compared to‘without blanching’.The operative activation energy and moisture diffusivity are described by using Fick’s law of diffusion.The calculation of effective moisture diffusivity can be done via the utilization of slope.The drying data is subjected to two models of mathematical nature:Simple Exponential model,and Page model.The performance of these models is examined by means of comparing the coefficient of determination(R2),chi-square(v2)and root mean square error(RMSE)between the experimental and forecasted value of moisture ratio obtained‘with blanching’and‘without blanching’.The experimental data was seen to be in accordance with the Page model.The comparisons of energy consumption,energy efficiency and also the cost of the drying processes for‘with blanching’and‘without blanching’have been accomplished to optimize and reduce process condition and the cost of the process,respectively.

Inhibition of α-amylase and α-glucosidase activities by ethanolic extract of Telfairia occidentalis (fluted pumpkin) leaf

Objective:To investigate the inhibitory effect of Telfairia occidentalis Hook f.(Curcubitaceae)(T.occidentalis)leaf on key enzyme linked to type-2 diabetes(α-amylase andα-glucosidase)as well as assess the effect of blanching(a commonly practiced food processing technique)of the vegetable on these key enzymes.Methods:Fresh leaves of T.occidentalis were blanched in hot water for 10 minutes,and the extracts of both the fresh and blanched vegetables were prepared and used for subsequent analysis.The inhibitory effect of the extract onα-amylase andα-glucosidase activities as well as some antioxidant parameter was determined in vitro.Results:The result revealed that unprocessed T.occidentalis leaf reduce Fe^(3+)to Fe^(2+)and also inhibitedα-amylase andα-glucosidase activities in a dose dependent manner.However,blanching of the leafy vegetables caused a significant(P<0.05)increase in the antioxidant properties but decrease their ability to inhibitα-amylase andα-glucosidase activities.Conclusions:This antioxidant properties and enzyme inhibition could be part of the mechanism by which they are used in the treatment/prevention of type-2 diabetes.However,the blanched vegetable reduces their ability to inhibit bothα-amylase andα-glucosidase activity in vitro.

Zinc Levels in Raw and Blanched Slenderleaf sp. (<i>Crotalaria ochroleuca</i>&<i>Crotalaria brevidens</i>) Indigenous Vegetables

An estimated 20% of the world’s population is at risk for zinc (Zn) deficiency. Micronutrient deficiencies are most prevalent in Africa and remain a major problem facing poor populations, whose impact is worsened by HIV/AIDS pandemic. Adequate zinc nutrition is essential for adequate growth, immunocompetence and neurobehavioral development. In Sub-Saharan Africa, Zn deficiency risk stands at 34.6% with 25.6% of its population having inadequate zinc intake. It is widespread in areas where diets lack diversity and it has been implicated as a contributing factor to stunting in approximately a third of children in low-income countries. In Kenya, it is a public health problem that about 50% of children under 6 years and 50% of women are affected. Zn deficiency rates are severe and pose severe consequences whose impact would translate into poor economic development and would set a vicious cycle effect that will take many generations to correct if left unchecked. It is important to examine zinc in the diet but its concentration in food varies depending partly on processing besides other factors. The objective of this study was to assess blanching as a food preparation method’s implication to Zn levels in vegetables. Blanching is a method where vegetables are dipped in boiling water for around two minutes and removed to avoid over cooking. Zn levels in slenderleaf sp. Indigenous vegetable commonly found in the Lake Victoria Basin region is not known. An experimental study was carried out to analyze zinc levels in raw and blanched slenderleaf sp. (Crotalaria ochroleuca & Crotalaria brevidens) vegetables. Results indicated that blanching reduces Zinc levels in slenderleaf vegetables, however, the reductions are not significant;the levels after blanching are still vital. It is, therefore, recommended to minimize blanching time in order to reduce loss of the vital nutrient in slenderleaf sp. vegetables.

Antioxidant Contents (Vitamin C) of Raw and Blanched Different Fresh Vegetable Samples

The study was aimed to determine the antioxidant contents and the effect of different blanching times (5 min, 10 min, 15 min and 20 min) on antioxidant contents of three different selected fresh vegetables. Three different types of vegeta- ble were used namely Amaranthus specie locally known as spinach, namely “tete”, (Celosia argentea), soko, (Solonum nodifiorum) and odu, (Telfeira occidentalis) were analyzed for their antioxidant contents. The analysis revealed that raw vegetables have the highest amount of antioxidant contents. Telferia occidentalis had the highest antioxidant content followed by Solonum nodifiorum. It was observed that blanching time had an adverse effect on the antioxidant contents of the blanched vegetables. The antioxidant contents of tete, soko and odu were significantly decreased (p < 0.05) after blanching.

Aflatoxin Carryover during Large Scale Peanut Butter Production

Peanut butter was monitored for aflatoxin contamination at different stages during its large-scale production starting from raw shelled peanuts up to the final product. Twenty five samples, weighing 2 kg each, were taken from each of the following stages: roasting at 160?C, blanching/de-skinning and grinding. The sub-samples were ground, thoroughly mixed and further reduced by the quartering technique until a 1 kg sub-sample was obtained. This was then analyzed for aflatoxins using reverse phase HPLC incorporating pre-column trifluoroacetic acid derivatization. The results showed a total aflatoxin percentage reduction of 51% after roasting, 27% after blanching/de-skinning followed by a further 11% after grinding to make peanut butter. This meant that there was a cumulative total reduction of 89% of aflatoxin concentration during the production process of peanut butter. These results show that there is a significant reduction of aflatoxin levels at the roasting and blanching stages in the process of producing peanut butter.

Polyphenol Oxidase Activity and Inhibition in White Yam （Dioscorea Rotundata. Var. Laasirin） Chips as African Fries for Human Consumption

Polyphenol oxidase, a bi-functional enzyme, has been implicated in enzymatic browning of yam and other tubers in a negative way. The objective of this present study was to examine the activity of polyphenol oxidase in Dioscorea rotundata. Var. laasirin and the efficiency of heat and chemical treatments in inhibiting this enzyme. Crude Polyphenol Oxidase （PPO） of Dioscorea rotundata.Var. Laasirin was isolated and the kinetics studied using the lineweaver-burk plot. The activity of the enzyme was evaluated using spectrophotomeric method. Yam PPO catalyzes oxidation of various substrates with catechol being the most readily oxidized substrate. The Michaelis-Menten constant （Km） and maximum reaction velocity （Vmax） for yam PPO were 0.00037 and 0.3125 respectively. Inhibition data showed that the enzyme had least activity （71.70） when blanched at 95℃ for 7 mins with chemical treatment involving a combination of 0.5% Sodium metabisulphite （Food grade） and 0.5% Ascorbic acid （Food grade）. The activity was highest （83.02） when it was blanched at 95 ℃ for 7 rains. This study has shown that it is possible to inhibit polyphenol oxidase activity in white yam using the chemical pretreatments and processing conditions described in this study for possible adoption in the production of packaged frozen yam chips by food industries.

Symbolic Representation of Blanche DuBois' s Tragic Fate in A Streetcar Named Desire

A Streetcar Named Desire is regarded as one of the most successful masterpieces of Tennessee Williams. An outstanding feature of the play is the wide use of symbolism. Symbols can be seen everywhere and even all the symbols in the play are con nected with the protagonist Blanche DuBois. Williams applies symbolism throughout the play to make Blanche's tragic fate more vivid to the readers. Her tragic fate lies in her clinging to illusion, thus she is bound to be abandoned by the harsh reality. There fore, the thesis attempts to give a comprehensive analysis of some specific symbols: symbols of illusion represented by the Chinese paper lantern and a paper moon, and symbol of reality represented by the light to further illustrate Blanche's tragically symbolic fate.

A World Destroys A World——On the Tragic Inevitability of Blanche

A Streetcar Named Desire, which has been widely accepted as the world-renowned work of Tennessee Williams, is a play with both of complexity and charm. After its publication, this play has attracted a lot of scholars and critics to interpret and study on it from the different aspects of views. The present paper attempts to certificate that the main character Blanche, in this play, who is live in a social background with the highlights of the conflict between the American southern plantation culture and the northern industrial civilization, suffers from the consistent change of her living space, her original world continually encounters destruction and invasion. Therefore, she has to step into another world; and she has to survive among different world. In addition, through digging into and interpreting the character Blanche, it investigates that people are of suffering and pain when they were in the process of adjusting and adapting themselves from their original world to their present- living world, and all Blanche's roads lead to a tragic.

A Study of Identity Crisis From the Perspective of Identity Negotiation Theory——Taking Blanche in A Streetcar Named Desire as Example

A Streetcar Named Desire unfolds the tragedy of a southern lady.The conflict betwixt southern Blanche and northern Stanley is the main contradiction in the play.In the end,Stanley drives Blanche crazy and sends her to an asylum.This paper attempts to analyze Blanche’s identity crisis from identity negotiation theory in cross-cultural communication,including identity security,identity inclusion,and identity predictability.Thereby it figures out that one who suffers hostile gazes from others in a strange environment,is unable to carry out an intimate and effective communication,which will eventually lead to a sense of loss and despair.This paper puts forward the methods to obtain identity recognition:be honest with others,be sure of oneself,and try one’s best to fit in the new environment,aiming to help people avoid identity crisis in interpersonal communication and establish a positive identity.

A Degenerated Southern Belle Ruined by Her Own Character

This article explores the fundamental elements which lead to the tragedy of Blanche, the heroine in Streetcar written by Tennessee Williams. In this drama, Williams tells us that we must accept the realistic view towards life, no matter how much we may dislike it, life only provides space for woman who is practical and conscientious, and not for those who are dissolute and live in illusions.

Livedoid Vasculopathy Secondary to Protein C Deficiency:A Case Successfully Treated With Rivaroxaban

Introduction:Livedoid vasculopathy is a chronic noninflammatory skin disease secondary to hypercoagulable states.No therapeutic guideline has yet been established for livedoid vasculopathy.We herein report a case of livedoid vasculopathy secondary to protein C deficiency that was successfully treated with rivaroxaban.Case presentation:A 31-year-old Thai woman who had been diagnosed with livedoid vasculopathy 10 years previously presented with a 2-month history of worsening leg ulcers and failure to respond to aspirin,colchicine,and pentoxifylline.Further investigations confirmed protein C deficiency.Rivaroxaban was initiated,and clinical improvement was achieved in 8 weeks.Discussion:When livedoid vasculopathy is confirmed by skin biopsy,additional investigations for hypercoagulable states should be performed to exclude secondary causes.Identification of the causes of livedoid vasculopathy can direct physicians to therapeutic options based on previously reported cases of successful treatment.Our patient,whose livedoid vasculopathy was caused by protein C deficiency,responded well to rivaroxaban.Conclusion:Protein C deficiency results in a hypercoagulable state,and affected patients can present with livedoid vasculopathy.The anticoagulant rivaroxaban has been beneficial in the treatment of livedoid vasculopathy.