QUALITY OF MAIZE HYBRIDS AS A RAW MATERIAL IN FUNCTIONAL, ORGANIC AND TRADITIONAL FOOD PRODUCTION

Milica Radosavljević, Valentina Semenčenko, Marija Milašinović-Šeremešić, Dušanka Terzić, Zorica Pajić, Goran Todorović

Yum Kaaz - Mayan Maize God

Maize (Zea mays) is a plant of enormous modern-day economic

importance as foodstuff and alternative energy source.

It was domesticated from the plant teosinte (Zea mays spp. parviglumis) in central America at least as early

9,000 years ago.

For western civilization, the story of maize began in 1492 when

Christopher Columbus's expedition discovered this new grain in Cuba.

At first, maize was only a garden curiosity in Europe,

however, it soon began to be recognized as a valuable food

crop.

Maize was first brought to Serbia in 1576 by Greek merchants.

By the end of the 18th century it became the predominant field crop, a staple food and an

indispensable part of our traditional cuisine (Bekrić, 1997).

Serbian village house in Maglič, around 1900; from:Srbija - zemlja i stanovništvo, F. Kanic, 1989

Importance of maize in food productionindustry is enormous...

... as well as in many other industries

TYPES OF MAIZE

There are five general types of maize: DENT, FLINT, FLOURY, POPCORN and SWEET CORN.

The predominant maize type grown in Serbia is dent, characterised by hard, dense endosperm at the sides and back of the kernel surrounding a soft core. Flint maize, the second most widely grown type, has smaller and rounder kernels than dent types, thick and hard endosperm surrounding a small soft centre.Floury maize differs from other types by very soft endosperm throughout the kernel and is remarkably easy to grind.

The eight-step process for extracting starch from maize. More than half of the maize processed into food and industrial products goes to the wet milling industry.

PRODUCTS:1. NATIVE MAIZE STARCH (yield 66-68%)2. MODIFIED STARCHES AND DEXTRINS3. SWEETENERS

BY PRODUCTS:1.STEEP WATER (yield 7-8%)2. GERM AND MAIZE OIL (yield 4+4%)3. HULLS AND FIBER (yield 11,5%)4. GLUTEN (yield 5,5%)

WET MILLING

DRY MILLING

The major steps of the dry milling process are tempering, degermination, drying and separation.

There are five main products resulting from a dry- mill: GERMHOMINY FEEDGRITSMEAL FLOURThe most valuable pieces of the kernel to the dry milling are the large endosperm pieces.

Maize is the nation’s #1 crop-the most important and

abundant crop produced in Serbia

FUNCTIONAL FOOD

Products with specific functions, known as functional foods, contain specific value-added ingredients (also known in isolated forms as “nutraceuticals”) that may act to prevent diseases and enhance the health and wellness of consumers.

Generally, functional food can be defined as any food product that is marketed or perceived to deliver a healthy benefit, in addition to its basic nutritional value (Biliaderis, 2008).

FOOD

Food grown or raised without the use of additives, coloring, synthetic chemicals (e.g., fertilizers, pesticides, hormones), radiation, or genetic manipulation.Medical Dictionary for the Health Professions and Nursing © Farlex 2012

Simply put, traditional foods are foods consumed in the way our ancestors ate them.  The basis is that the food you consume be as nutrient dense and nourishing as possible.  Traditional foods goes beyond just avoiding packaged and processed foods.  It is about choosing the best food options available for your budget, individual chemistry & location and consuming it in a way that allows your body to extract the maximum nutrition from that item.

TRADITIONAL FOOD

TOTAL, DIETARY AND FUNCTIONAL FIBER

Total fiber is the sum of dietary fiber and functional fiber. Dietary fiber include non-digestible carbohydrates and lignin most

commonly found in plants. Functional fiber is defined as isolated, manufactured, or synthetic

oligosaccharides with three or more degrees of polymerization found in both plants and animal products that play an important role in several beneficial physiological functions, including effects on laxation, blood glucose, and cholesterol concentrations, in reducing the incidence of diverticulosis, cardiovascular disease, and some cancers (1,2).

1 Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) Food and Nutrition Board and Institute of Medicine. The National Academies Press. (2002) 2 Gallaher, DD and BO. Schneeman. Dietary Fiber Chapter.Present Knowledge in Nutrition; ILSI Press; Washington D.C.; 2001; pp. 83-91.

STARCH The most important reason for advantage

of maize over other cereals in human nutrition is certainly its high starch content, i.e. the high energy content.

Molecular formula: (C6H10O5)n Complex carbohydrate made up of two components Components:

Amylose Amylopectin

Properties depend on amounts of the components.

Maize starch in polarized light

Schematic representation of a starch granule

Amylose AmylopectinShape: essentially linearLinkage: -1,4 (some -1,6)Molecular weight: <0.5 millionFilms: strongGel formation: firmColor with iodine: blue

Shape: branchedLinkage: -1,4 and -1,6Molecular weight: 50-500 millionFilms: weakGel formation: non-gelling to soft Color with iodine: reddish brown

*Source: Radosavljević, 1985

APPROXIMATE AMYLOSE AND AMYLOPECTIN CONTENT OF COMMON MAIZE STARCHES

Starch type Amylose (%) Amylopectin (%)

Dent maize 25 75

Waxy maize <1 >99

High amylose maize

55-70 (or higher)

45-30 (or lower)

Resistant starch is the sum of starch and starch degradation products not absorbed in the small intestines of healthy individuals.Included in the definition of dietary fibre - demonstrates similar physiological benefits.The regulation of body weight (increased fiber intake, reduced energy value of food, increase satiety, helps burning lipids).Helps regulation of blood glucose and good health of the colon and digestive system.Applications of resistant starch in foods have become a trend among food manufacturers to improve the health and well-being of consumers.Addition of resistant starch to food products improves the sensory properties and texture of the product Increases content of dietary fiber and prolongs the freshness of products.

CLASIFICATION OF RESISTANT STARCH (Nugent, 2005)

.Type Description Food sources

RS1 Physically protected

Whole- or partly milled grains and seeds, legumes

RS2

Ungelatinized resistant granules with type B crystallinity, slowly hydrolyzed by α-amylase

Raw potatoes, green bananas, some legumes, high amylose corn

RS3 Retrograded starch

Cooked and cooled potatoes, bread, cornflakes, food products withrepeated moist heat treatment

RS4

Chemically modified starches due to cross-linking with chemical reagents

Foods in which modified starches have been used (for example, breads, cakes)

OBJECTIVE

The main objective of this study was to:

Observe the grain quality of different maize hybrids developed at the Maize Research

Institute, Zemun Polje as a raw material for use in maize-based food products, i.e. - to

determine the end-use value of these maize hybrids for functional, organic and traditional

food production.

MATERIAL

Maize hybrids, of different maturity groups (FAO 100-800) and various types were studied: including genotypes of standard chemical composition as well as specialty hybrids such as popcorn, waxy, white and red kernel hybrids, developed at the Maize Research Institute, were investigated in this study.

METHODS

Physical properties and chemical composition of the maize hybrids grain were determined by standard laboratory procedures.

PHYSICAL PROPERTIES

1. Test weight (bulk density)

2. 1000-kernel weight (absolute weight)

3. Kernel density

4. Flotation index

5. Water absorption index

6. Kernel hardnessCHEMICAL PROPERTIES

1. Protein (micro-Kjeldahl method)

2. Starch (Ewers method)

3. Oil (Soxhlet method with diethylether as solvent)

METHODS

The modified Van Soest detergent method was applied to determine lignocellulose fibres (NDF - neutral detergent fibres, ADF - acid detergent fibres, ADL - acid detergent lignin) (Mertens, 1992). In vitro digestibility of the whole maize plant samples was performed by the Aufréré +method (2006) based on enzymatic solubility . Resistant starch content was determined according to the enzymatic-gravimetric method (AOAC 991.43) and McCleary method (2002).

RESULTS

KERNEL PHYSICAL PROPERTIES OF ZP MAIZE HYBRIDS

Hybrid 1000- kernel

weight (g)

Test weight (kg∙m-3)

Density (g∙cm-3)

Flotation index (%)

Milling response

(s)

Hard endosperm

(%)

Soft endosperm

(%)ZP 161 185.28 778.35 1.22 66 36 17.80 60.18 39.82ZP 173 215.38 759.87 1.20 85.41 12.67 58.61 41.39ZP 341 250.26 797.09 1.25 40.03 12.00 55.52 44.48ZP 377 236.54 784.75 1.25 24.86 12.73 58.95 41.05ZP 388 243.93 787.58 1.25 27.00 11.77 59.09 40.91ZP 427 282.83 763.47 1.23 89.79 11.17 54.30 45.70ZP 434 272.33 797.23 1.24 66.70 11.07 57.15 42.85ZP 440 256.57 761.87 1.22 88.85 10.60 56.02 43.98ZP 444 254.77 802.70 1.24 19.95 11.37 60.15 39.85ZP 461 252.37 755.96 1.20 81.58 15.13 54.96 45.04ZP 503 295.77 782.17 1.23 73.12 12.40 58.59 41.41ZP 555 247.67 788.85 1.24 44.28 11.17 59.10 40.90ZP 560 270.95 800.36 1.26 28.00 10.90 59.94 40.06ZP 585 297.92 774.25 1.23 77.32 10.30 56.73 43.27ZP 588 230.68 812.41 1.28 15.72 15.10 59.85 40.15ZP 600 290.39 761.44 1.24 73.92 12.43 54.60 45.40ZP 606 300.30 756.08 1.23 93.78 12.10 52.87 47.13ZP 611k 122.84 883.57 1.38 1.85 30.10 79.03 20.97ZP 614k 114.06 880.28 1.31 3.12 30.53 78.90 21.10ZP 620b 248.26 774.07 1.24 53.59 11.60 59.65 40.35ZP 623 258.57 746.92 1.21 91.67 11.53 51.48 48.52ZP 643 213.42 817.54 1.28 14.16 16.07 61.53 38.47ZP 648 303.47 756.43 1.21 95.52 10.67 52.12 47.88ZP 666 250.12 802.61 1.26 30.62 13.13 60.90 39.10 ZP 667 269.09 760.77 1.22 95.08 9.50 51.20 48.80ZP 684 225.85 755.34 1.21 74.62 11.70 54.83 45.17ZP 718b 274.88 821.51 1.40 19.79 12.53 62.15 37.85ZP 725 265.84 766.78 1.21 87.73 13.37 53.69 46.31ZP 749 263.01 745.14 1.20 95.55 10.07 52.48 47.52ZP 750 280.57 746.75 1.22 90.45 11.80 57.62 42.38ZP 758 262.34 750.17 1.20 98.29 10.53 53.31 46.69ZP 761b 241.94 770.69 1.26 46.09 11.00 60.18 39.82ZP 789 263.61 771.30 1.21 83.61 11.33 53.20 46.80ZP790 258.04 779.57 1.22 81.18 11.07 54.87 45.13ZP 802 273.31 769.53 1.22 87.30 10.00 53.06 46.94ZP 873 236.94 761.17 1.23 73.36 10.80 57.57 42.43

KERNEL HARDNESS

CHEMICAL COMPOSITION OF THE INVESTEGATED ZP HYBRIDS KERNEL

HYBRID STARCH (%) PROTEIN (%) OIL (%)CRUDE FIBER

(%)ASH (%)

ZP 161 68.00 11.17 6.07 2.46 1.42ZP 173 67.26 11.49 5.61 2.11 1.43ZP 341 66.27 10.60 6.39 2.17 1.40ZP 377 67.67 10.48 5.75 1.97 1.37ZP 388 66.66 10.05 5.44 1.85 1.36ZP 427 66.60 10.65 7.29 1.89 1.47ZP 434 66.86 10.64 6.22 2.17 1.37ZP 440 67.34 10.47 5.65 2.18 1.42ZP 444 66.78 10.62 5.99 1.95 1.34ZP 461 67.47 11.56 5.27 1.99 1.43ZP 503 69.15 10.42 5.38 2.08 1.25ZP 555 69.76 10.10 5.73 2.28 1.22ZP 560 66.47 10.65 5.84 1.99 1.33ZP 585 66.13 11.11 5.96 2.20 1.34ZP 588 67.87 9.91 5.90 2.04 1.33ZP 600 70.52 9.95 6.50 1.84 1.40ZP 606 69.28 10.01 5.58 2.15 1.31ZP 611k 65.00 13.20 5.91 2.65 1.47ZP 614k 65.33 13.17 5.17 2.41 1.46ZP 620b 67.49 9.71 6.04 2.54 1.35ZP 623 70.91 9.86 6.20 2.23 1.41ZP 643 68.49 10.29 5.50 2.58 1.40ZP 648 70.34 10.51 5.25 2.09 1.50ZP 666 69.89 10.53 5.86 2.63 1.41ZP 667 71.15 9.87 5.65 1.97 1.29ZP 684 69.27 11.01 5.45 2.05 1.47ZP 718b 67.22 9.96 5.78 2.45 1.36ZP 725 69.48 10.09 5.73 1.99 1.35ZP 749 68.49 10.91 5.19 2.02 1.42ZP 750 69.64 10.74 5.06 2.10 1.46ZP 758 69.17 10.56 4.93 2.27 1.44ZP 761b 67.79 10.50 5.87 2.17 1.36ZP 789 69.25 10.45 5.28 1.89 1.36ZP790 70.75 9.76 6.70 1.87 1.36ZP 802 70.55 9.75 5.87 2.01 1.33ZP 873 67.99 10.00 5.97 2.12 1.42

KERNEL STRUCTURE OF ZP MAIZE HYBRIDS

ZP 1

61

ZP 3

88

ZP 4

44

ZP 5

60

ZP 6

06

ZP 6

23

ZP 6

67

ZP 7

49

ZP 7

89

0.00

20.00

40.00

60.00

80.00

100.00

Pericarp (%) Germ (%) Endosperm (%) 4.79% (ZP 677) -9.64 % (ZP 614k) 9.67% (ZP 614k) - 13.35% (ZP 620b) 79.97 % (ZP 718b) – 84.83% (ZP 667)

LIGNOCELLULOSIC FIBRE COMPOSITION AND DIGESTIBILITY OF ZP MAIZE KERNEL

HYBRIDNDF(%)

ADF(%)

ADL (%)

HEMICELLULOSE (%)

CELLULOS

E(%)

IN VITRO DRY MATTER

DIGESTIBILITY(%)

ZP 173 21.04 3.63 0.73 17.41 2.90 88.40ZP 341 23.36 2.63 0.35 20.73 2.29 88.21ZP 377 22.52 2.37 0.25 20.15 2.13 89.97ZP 388 16.78 3.48 0.69 13.30 2.78 92.68ZP 427 21.58 2.31 0.30 19.27 2.01 93.14ZP 434 14.04 3.77 0.76 10.27 3.01 87.70ZP 440 22.91 3.26 0.37 19.65 2.89 91.01ZP 444 22.16 3.61 0.53 18.55 3.08 91.45ZP 461 24.42 3.18 0.37 21.24 2.82 89.38ZP 555 15.28 4.46 0.69 10.82 3.77 85.26ZP 560 14.97 4.41 0.72 10.56 3.70 90.71ZP 585 11.42 3.78 0.46 7.64 3.32 90.27ZP 588 18.18 4.76 0.85 13.42 3.91 88.82ZP 606 11.22 4.03 0.61 7.19 3.43 91.09ZP 611k 10.10 5.08 0.89 5.02 4.19 92.13ZP 648 16.71 2.13 0.26 14.58 1.87 91.25ZP 666 20.51 2.69 0.36 17.81 2.34 91.63ZP 684 18.16 3.88 0.53 14.28 3.36 91.40ZP 718b 17.61 4.44 0.75 13.17 3.69 88.91ZP 758 17.90 2.40 0.20 15.50 2.20 89.97ZP 790 16.31 3.84 0.50 12.51 3.30 89.00ZP 802 17.17 2.27 0.23 14.90 2.04 88.81

STARCH QUALITY OF ZP HYBRIDS OBTAINED BY WET MILLING PROCESS

62.4161.6766.3465.25

62.3264.2967.4366.9968.34

61.19

85.6183.86

94.1590.39

84.9189.2 90.1590.3591.6593.53

Starch yield, % Starch recovery, %

*Source: Semenčenko, 2013

STARCH

Hybrid Protein content (%)

Digestibility(%)

ZP 172/8 0.21 90.07ZP 243 0.20 89.56ZP 341 0.17 90.16ZP 434 0.26 91.24ZP 505 0.23 89.84ZP 548 0.26 91.40ZP 677 0.27 89.93ZP 704wx 0.22 92.74ZP 808 0.16 88.15ZP Rumenka 0.19 89.72

AVERAGE REDUCING SUGARS, SUCROSE, AMYLOSE AND AMYLOPECTIN CONTENT OF THE INVESTIGATED

HYBRIDS KERNEL AND STARCH

24%

76%

Average amylose content (%)

Average amylopectin content (%)

Min Max0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

0.190.58

1.96

3.21

Reducing sugars content (%)

Sucrose content (%)

RESISTANT STARCH The resistant starch (RS) content in native starch of different ZP

maize hybrids was very low and ranged from 0.62 to 1.61% and 0.00 to 0.85% depending on the applied methods.

The method developed by McCleary gave lower values for the RS content although this method allows a greater deviation for low RS concentrations in samples (<2%).

RESISTAN STARCH CONTENT IN THE ISOLATED STARCHES

Starch source RS (%) (AOAC Official

Method 991.43)

RS (%) (McCleary

Method, 2002)

ZP 74 b 1.14 ± 0.09 0.55 ± 0.20

ZP 360 1.17 ± 0.04 0.70 ± 0.03

ZP 578 1.26 ± 0.15 0.71 ± 0.10

ZP 611 1.50 ± 0.21 0.80 ± 0.01

ZP 704 wx 0.62 ± 0.24 0.00 ± 0.00

ZP 808 1.61 ± 0.11 0.78 ± 0.10

ZP Rumenka 1.41 ± 0.07 0.85 ± 0.05 *Source: Milašinović-Šeremešić et al, 2012 (APTEF,43,61-68)

SPECIALITY HYBRIDS The grain yield and popping volume are most important parameters of

popcorn quality. Due to the higher yield and popping volume, new popcorn hybrids have

almost completely replaced local varieties. The popping expansion (volume) is defined as a volume of popped

kernels in relation to the kernels that are not popped.

GRAIN YIELD AND POPPING VOLUME OF ZP POPPING MAIZE HYBRIDS

Hybrid Grain yield (t∙ha-1)

Popping volume (cc∙g-1)

ZP 611k

6.4 42

ZP 614k

6.8 42*Source: Commission for the Variety Releasing of the Republic of Serbia, and Pajić et al., 2010 (Genetika, Vol. 42, No 1, 57-66)

oWhite kernel maize is a type of maize with the endosperm of white color without hues of the yellow color. oBesides the yield, a pure white color of kernels is a trait important for these hybrids.

CONCLUSIONSThe obtained results showed a wide range of quality parameters among the investigated ZP maize hybrids. The observed differences in maize grain starch, its structure and functional properties, as a basic component in the food production, as well as variations in protein, oil, crude fibre and resistant starch content, and in vitro digestibility among the investigated maize hybrids grain, further increase the end use value of these maize hybrids. Obtained results are of an exceptional importance for the selection of potentially most suitable maize hybrids for the production of functional, organic and traditional food.

FOOD PRODUCTS

Some of the products made from white, yellow and red kernel ZP maize hybrids flour have been previously introduced to the market.

Department of Food Technology and Biochemistry, Maize Research Institute, Zemun Polje

This research is a result of the project TR 31028, funded by the Ministry of Education, Science and Technological

Development of the Republic of Serbia.

Thank you for your attention!