synthesis of resistant starch 2.ppt

Research design Sampling Cassava Varieties

Starch extraction

Determination of Resistant Starch (RS)

Hydrothermal modification of RS (Synthesis of RS)

Application of RS in Yogurt processing

Lab and Sensory evaluation

CHAPTER THREE: MATERIALS AND

METHODS

University of Nairobi ISO 9001:2008 1 Certified http://www.uonbi.ac.ke

Raw material acquisitionCassava roots samples from three different cassava varieties (NASE14, THE I92/0057 and GARUKUNSUBIRE) of 12 months in the field will be collected from RAB field research stations of Rubona and Rilima

Starch extracting

Measurement of RS

Objective 1: Determination of

the levels of RS in three Rwandese

cassava varieties


Starch Extraction Starch will be extracted using the wet method as described

by Benesi et al. (2004).Starch properties • Moisture content and dry matter content determination

(ISO 1660 -1996),• Water absorption and Solubility Index will be carried out

as per Anderson (1982), •Texture analysis: Texture Analyser will be used (Kaszab et al., 2002),• Pasting profile of starch (AACC Approved Method 61.02.).

Determination of the levels of RS in three

Rwandese cassava varieties con’t


Resistant starch determinationRS will be determined as per AOAC Method (2002.02).Triplicate samples will be analyzed and ANOVA will be carried out to determine significant differences at 5% level of significance.

Determination of the levels of RS in three

Rwandese cassava varieties con’t


Heat-moisture treatment (HMT) The moisture levels of the starch samples will

be increased to 18%, 24% and 30%, The samples will be sealed in glass jars and

heated in an air oven at 80°C for 16 hours, The starch samples will be air dried and

subjected to RS measurement.

Objective 2: Hydrothermal

modification of RS


Annealing Starch (100g) will be heated in excess water

at a temperature of 45°C and 55°C for 24 hours,

Samples will be centrifuged, air-dried and will be subjected to RS determination.

Hydrothermal modification of RS

cont’


Starch profiling•Moisture content and dry matter content determination (ISO 1660 -1996),•Water absorption and Solubility Index will be carried out as per Anderson (1982), • Texture analysis: Texture Analyser will be used

(Kaszab et al., 2002),•Pasting profile of starch (AACC Approved Method 61.02.).


cont’


Pasting profile of starch (AACC Approved Method 61.02.)Flour (40 g) and water (420 ml) will be heated from 30°C to 93°C and held for 15 min, The temperature will be decreased at a constant rate of 1.5°C/ min until 30°C and held there for 15 min.The resistance to stirring as a viscosity curve will be recorded,

The pasting temperature, peak viscosity, hot paste viscosity and cold paste viscosity will be determined from the pasting curve.


cont’


Data analysis A 3x5 factorial design will be usedEach experiment will be done in triplicateTotally, 45 treatments will be analysed in GenStat application

N45 : Annealing at 45°C AN55 : Annealing at 55°CHMT-18: 18% M.C HMT-24: 24% M.C HMT-30: 30%M.C

Hydrothermal modification of RS cont


Treatments HMT-18

HMT-24

HMT-30

AN-45 AN-55Varieties

NASE14THE I92/0057 GARUKUNSUBIRE

yoghurt will be treated with 0.1%, 0.5% and 1% of cassava starch with high RS levels as thickener,

Yoghurt with no thickener will be used as a control

Objective 3: Application of resistant

starch in yoghurt


Application of resistant starch in

yoghurt con’t


Preliminary treatment of milk (standardization)

Homogenization

Starch Heat treatment (950C for 15 Min)

Cooling (430C) Starter culture

Inoculation with starter culture

Stirred yogurt

Packaging (250C)

Cooling and storage (50C)

Sensory Evaluation

Analysis of yoghurt Texture analysisTexture Analyser will be used to objectively evaluate the

texture of modified yoghurt as per Kaszab et al. (2002). Viscosity analysisViscosity will be measured by Viscometer as per

Djurdjević et al., 2001. Syneresis By centrifugation Method pH and Acidity (Titration) Total solids : ISO 13580: 2005 Levels of RS


yoghurt con’t


Sensory evaluation A panel of 20 people will be tasked to evaluate the quality characteristics (taste, colour, flavour, aftertaste, texture and overall acceptability),

A 7 point hedonic scale will be used: where 7= like very much, 6= like moderately, 5= like slightly, 4= dislike slightly, 3= dislike moderately, 2= dislike very much and 1= dislike extremely.


yoghurt con’t


Scoresheet

Data analysis Sensory evaluation data will be analysed in a complete randomised design


yoghurt con’t


parameter

Colour

Taste Flavour

Aftertaste

Texture

Overall acceptanceSamples

Untreated0.1%0.5%1%

WORK PLAN


Proposed Budget


THANK YOU


synthesis of resistant starch 2.ppt

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