effect of moisture content, postharvest treatment, and storage time on some properties and quality...
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Effect of moisture content, postharvest treatment, and storage
time on some properties and quality attributes of red lentil
Yang Zhang a
L.G. Tabilb, X. Lib, A. Opokub, Decheng Wanga, G. Argañosab
a China Agricultural Universityb University of Saskatchewan
2008 CSBE/SCGAB Annual Conference
2008 CSBE/SCGAB Annual Conference
IntroductionLentil (Lens culinaris L.), is one of the
most nutritious pulse grains due to its high content of plant protein.
Majority of red lentil is consumed after primary processing--dehulling.
Red LentilGreen Lentil Green Lentil
Introduction Dehulled lentil is consumed in whole
cotyledon (footballs) or in split cotyledon.
Dehulling
Dehulled football
Dehulled split
Cooking is the most traditional practice used to convert red lentil into consumable foods.
2008 CSBE/SCGAB Annual Conference
Introduction Some conceptions Water absorption—defined as the maximum
amount of water that 100 intact red lentils absorb at room temperature.
Dehulling efficiency—defined by the percent of dehulled whole seeds (%) and dehulled split seeds (%) obtained relative to the initial sample mass.
Cooking time—defined as the time required for 80% of the red lentil to be cooked.
2008 CSBE/SCGAB Annual Conference
Introduction What’s the problem? Basic physical properties Quality attributes
1. Dehulling quality—dehulling efficiency
2. Cooking quality—cooking timeChemical components
2008 CSBE/SCGAB Annual Conference
Objective Physical properties
100-seed weight
Water absorption
Dehulling quality
Cooking quality
Protein content
Moisture content
Postharvest treatment
Storage time
2008 CSBE/SCGAB Annual Conference
Methods Sample preparation Postharvest treatment
Storage time 0 month , 1 month , 2 months and 4 months
Red Lentil “Robin” Mc=10.07%
Mc=11.31%
Tempering
Initial McMc=9.62% Storage Temp. 5 ℃
Storage Temp. 25 ℃
2008 CSBE/SCGAB Annual Conference
Methods Measurement and apparatus Dehulling efficiency Cooking Time
Satake grain testing mill Automated Mattson cooker
2008 CSBE/SCGAB Annual Conference
a-PC; b-I/O card; c-interface box; d-circuit board assembly; e-actuator; f-plunger; g-Mattson cooker.
The abrasive wheel--1100 rpm; Time--38 s.
From: Canadian Grain Commission
Results – 100-seed weight
Sample (Moisture content, % w.b. and postharvest treatment)
100-seed weight (g)
Storage Time (month)
0 1 2 4
9.62% 5℃ 2.7591±0.0107 2.7463±0.0016 2.7342±0.0084 2.7176±0.0051
10.07% 5℃ 2.7829±0.0410 2.7768±0.0152 2.7748±0.0166 2.7687±0.0045
10.07% 25℃ 2.8183±0.0066 2.7987±0.0379 2.7920±0.0134 ------
11.31% 5℃ 2.8434±0.0380 2.8228±0.0128 2.8185±0.0197 2.8118±0.0141
11.31% 25℃ 2.8748±0.0090 2.8420±0.0086 2.8245±0.0167 ------
2008 CSBE/SCGAB Annual Conference
Dehulling efficiency
Note: Values (mean of three replicates) in the same column followed by the same letter are not significantly different by Duncan’s multiple range test (P < 0.05).
Results – Dehulling quality
Sample (Moisture content, % w.b. and postharvest treatment)
Dehulling Efficiency (%)Storage Time (month)
0 1 2 4
9.62% 5℃ 86.77 86.66 a 86.53 a 86.51 a10.07% 5℃ 86.72 86.65 a 86.54 a 86.46 a10.07% 25℃ 86.49 86.23 b 86.33 a ------11.31% 5℃ 86.71 86.12 b 85.77 b 85.75 b11.31% 25℃ 86.27 85.60 c 85.10 c ------
2008 CSBE/SCGAB Annual Conference
Cooking time
Results – Cooking quality
Sample (Moisture content, % w.b. and postharvest treatment)
Cooking time (min)Storage Time (month)
0 1 2 4
9.62% 5℃ 1.595 1.947 2.403 3.05710.07% 5℃ 1.651 2.213 2.700 3.30910.07% 25℃ 1.991 2.338 2.946 ------11.31% 5℃ 1.940 2.797 3.266 3.77311.31% 25℃ 2.350 2.923 3.365 ------
2008 CSBE/SCGAB Annual Conference
Results – Protein content
2008 CSBE/SCGAB Annual Conference
The relationships between protein content and moisture content over 0, 1, 2 and 4 months’ storage could be represented by the following equations:
cc M.-.P 2020 27700
cc M.-.P 2030 27301
cc M.-.P 5750 30602
cc M.-.P 5030 29604
(R2 = 0.88)
(R2 = 1.00)
(R2 = 1.00)
(R2 = 0.99)
Conclusions Considering moisture content only, the 100-seed weight
and the cooking time of red lentil increased in the moisture content range; while the ability of water absorption, dehulling efficiency, and protein content decreased in the moisture content range.
Considering postharvest treatment and storage time, the protein content of red lentil stored at 5 , 100-seed ℃weight, water absorption, and dehulling efficiency decreased within the storage period, while positive trends in the protein content for the red lentil stored at 25 and ℃the cooking time were found during the storage period.
High temperature and long storage time adversely affect the dehulling quality and cooking quality of red lentil.
2008 CSBE/SCGAB Annual Conference
Conclusions Further studies should be conducted on more
variability of chemical and nutritional properties under different postharvest treatments and different storage time, such as the contents of starch, phytic acid, and calcium, to better understand the influence factors on cooking quality of red lentil. Also a wider moisture range and longer storage time should be involved in further studies.
2008 CSBE/SCGAB Annual Conference