Storage Temperature and Grain Moisture Effects on Market and End Use Properties of Red Lentil

Abstract

Storing lentil is a strategy used by growers to manage price volatility. However, studies investigating the impact of storage conditions on the market and end use properties of lentil are limited. This study examined the effects of storage temperature (4, 15, 25, and 35 °C) and grain moisture (10 and 14%, w/w) on traits related to market (seed coat colour), viability (germination capacity), and end use properties (hydration capacity, milling efficiency, and cooking quality) in four red lentil cultivars (PBA Bolt, PBA Hallmark, PBA Hurricane, PBA Jumbo2) over 360 days. Storing lentil at 14% moisture content and 35 °C significantly (p = 0.05) darkened seed coat after 30 days, caused complete loss of viability within 180 days and reduced cooking quality (cooked firmness) after 120 days across all tested cultivars. Storing lentil at 10% moisture content and 35 °C reduced hydration capacity after 30 days, and milling efficiency after 120 days across all cultivars tested. PBA Jumbo2 exhibited a higher rate of degradation in hydration capacity and cooking quality, and a lower rate of degradation in the other traits studied. Storing lentil at ≤15 °C prevented degradation of all quality traits. These findings will support improved lentil storage protocols to maintain quality and improve economic outcomes for the pulse industry.

Storage Temperature and Grain Moisture Effects on Phenolic Compounds as a Driver of Seed Coat Darkening in Red Lentil

“…In this study, grain samples from two contrasting red lentil cultivars (PBA Hallmark and PBA Jumbo2) were obtained from a previous study [7]. Both cultivars were stored under a factorial combination of two moisture contents (10 and 14%, w/w) and two contrasting temperatures of 4 and 35 • C for 360 days.…”

“…In current cultivars, it has been shown that the colour of the lentil seed coat is unstable and subject to change over time based on storage conditions and length of storage, shifting from a bright light to a duller or darker shade [6]. Previous research has identified the seed coat of red lentil changes to a deep brown colour when stored at or above 25 • C and under high grain moisture content (14%, w/w) [7]. Changes in seed coat colour in pulse grains have been linked to a reduction in bioactive compounds such as phenolic compounds in faba beans [8] and green lentil [6] subjected to extended storage periods.…”

An Explanatory Model of Red Lentil Seed Coat Colour to Manage Degradation in Quality during Storage

“…The seed coat colour of lentil is an economic determinant for growers and traders as it strongly influences the marketability and value of the grain. The colour of the seed coat darkens over time particularly under extreme storage conditions and is primarily attributed to environmental factors such as temperature and grain moisture content [1]. Depending on the lentil grain moisture content and temperature at harvest as well as external weather conditions such as seasonal and daily variation in temperature during storage, the lentil seed coat can substantially darken.…”

“…Depending on the lentil grain moisture content and temperature at harvest as well as external weather conditions such as seasonal and daily variation in temperature during storage, the lentil seed coat can substantially darken. This can result in reduced marketability, the downgrading of the stored grain and, consequently, lower profits for growers [1].…”

“…However, the monitoring of the quality of the grain, such as the decline in seed coat colour, is limited. There were two aims of this study: (1) to develop and validate an explanatory biophysical model which predicts the changes in seed coat brightness (CIE L*), redness (CIE a*), and yellowness (CIE b*) of stored lentil grains over time across diverse storage conditions and (2) to simulate the impact of several storage scenarios on lentil grain quality in order to understand the broad sensitivity analysis of lentil seed coats under various storage conditions.…”