Food Protection Trends - January/February 2022 - 26

the " Pulse Advisor, " lentils can be combined (harvested) at 16
to 18% moisture; chickpeas can be harvested at 18% moisture,
and peas at 18 to 20% (3). Premature harvest of high-moisture
pulses is avoided because the product may mold, ferment, or
split during storage. Chickpeas and green lentils must be stored
at less than 14% moisture and peas at less than 16% to prevent
molding during product storage. Final maximum moisture
levels to meet U.S. Department of Agriculture (USDA)
grading standards for U.S. #3 grade are 15% for dry peas,
14% for lentils, and 18% for chickpeas (17).
POSTHARVEST HANDLING
Pulses can be stored after harvest for up to 2 years under
optimum conditions and in some cases for 3 to 4 years. Much
of the crop may be stored on the farm or delivered to country
elevators at harvest time, before it is cleaned, packed, and
distributed. If high moisture is a problem, chickpeas and lentils
can be stored in aerated hopper-bottom bins (2).
Without dry, cool conditions during storage (i.e., <16%
moisture and <15°C [59°F] for dry peas), pulses may be
susceptible to spoilage by mold and insect infestation. Pulses
are rarely infested when stored under dry, cool conditions
(3), but stored grain insects of concern include the dry bean
weevils (bruchids): vetch weevil (Bruchus brachialis Fahraeus),
pea weevil (Bruchus pisorum L.), broadbean weevil (Bruchus
rufimanus Boheman), and bean weevil (Acanthoscelides
obtecetus (Say)) (3). Bean weevils also can attack beans and
peas when they are in the field (18) and can continue to breed
in dry seeds if stored in a warm place. The lepidopteran Indian
meal moth (Plodia interpunctella (Hübner)) also can attack
dried peas and beans, leaving webbing and frass from larvae
feeding on product that is split or has cracked seed coats.
Bruchids are controlled by sanitation and inventory control
in the elevator facility (15). Additional controls for stored
product insects include placing diatomaceous earth in the
bottom of storage bins. This material acts as an insecticide by
absorption of insect cuticle lipids and fatty acids, resulting in
desiccation and death.
FURTHER PROCESSING AND USE OF PULSES
Dry peas are traditionally used in soups, casseroles, stir
fry dishes, salads, and pot pies, always after the dry hard
seeds are rehydrated (2). Canned dry peas are soaked for
10 to 15 h, blanched at 88°C to 93°C (190 to 199°F) for 4
to 6 min, and brined and filled into cans in preparation for
commercial sterilization.
Peas also can be further processed through a cleaning, seed
coat-heating, and splitting process into split peas (Fig. 11),
a popular soup ingredient in North America and Europe. In
Asian countries, whole dry peas may be roasted or fried and
consumed as a snack. This process involves rehydrating dry
product for 8 to 10 h at room temperature before frying in oil.
A more recent use of dry peas is fractionation into pea
protein and pea starch. These ingredients are made through
26
Food Protection Trends January/February
either dry or wet fractionation processes that take advantage
of the difference in physical properties of starch- and proteincontaining
particles (2). Pea protein is used as a protein
booster in such foods as nutritional bars, nondairy creamers
and yogurts, and meat substitutes.
Chickpeas may be further processed through extensive
cooking, canning, or milling into flour. A popular dip made
from cooked garbanzos in the Middle East and North America
is hummus. Like dry peas, chickpeas may be roasted to create
a snack food. Pulses can be either wet or dry milled into flour
products. Chickpea flour (sometimes known as gram flour)
also is used as an alternative to wheat flour in gluten-free
baked goods and for other cooked products such as falafel
and farinata. The normal intended use of pulse flour calls for
further cooking or baking before consumption.
In the Americas and Europe, lentils are typically prepared in
soups. They may be further commercially processed through
cooking, freezing, and canning. A lentil stew made with spices
and water known as dhal is consumed regularly in India and
South Asia.
Regardless of the final use of pulses, they must be cooked
before consumption to assume an edible, palatable state. The
only exception would be sprouting pulses for which there is
not a thermal processing step and they thus poses a higher
risk for biological hazards, such as Escherichia coli, Salmonella,
and Giardia. Sprout production falls under the Produce Safety
rule (24), 21 CFR 112, and is addressed specifically in the
FSMA guidance " Compliance with and Recommendations for
Implementation of the Standards for the Growing, Harvesting,
Packing, and Holding of Produce for Human Consumption
for Sprout Operations: Guidance for Industry Draft Guidance,
2017 " (29).
POTENTIAL FOOD SAFETY HAZARDS OF
PULSES
During growing and storage, beans and chickpeas may be
exposed to potential biological, chemical, and physical food
safety hazards. Under the right conditions, many types of
fungi and bacteria can grow on pulses, including Aspergillus,
Cladosporium, Fusarium, Penicillium, Rhizopus, Rhizoctonia,
and Macrophomia (4, 15). Fusarium and Aspergillus are
the most probable mycotoxin-producing fungi in beans.
Mycotoxin presence is correlated with seed discoloration
(14). Examples of storage fungi include Aspergillus halophilicus
and Aspergillus glaucus, and growth occurs during storage of
beans for 6 months or longer at a high moisture content. A.
halophilicus has not been found to produce compounds toxic
to humans and animals (4), whereas A. glaucus and Aspergillus
candidus have the potential to produce toxic compounds when
beans are used as animal feed. Aspergillus parasiticus has been
found to produce aflatoxins in navy, kidney, and pinto beans
at 20% moisture content and at 21, 28, and 35°C. Ochratoxin
and aflatoxin can be produced by Aspergillus ochraceus and
Aspergillus flavus. Several species of Penicillium may be
Food Protection Trends - January/February 2022

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