Nut Grower's Guide

The Complete Handbook for Producers and Hobbyists

Jennifer Wilkinson

• Publisher: Landlinks Press
• Year: 2005
• ISBN:
  9780643099340
• Topic: Biological Sciences
• Subtopic: Horticulture
• Index: Biological Sciences

Nut growing has become more popular and technology has developed significantly over the last 5 years. This book is the starting point for prospective commercial nut growers – large or small scale, for farmers who want to diversify and also for gardeners interested in growing nut trees in their back yards.

Nut Grower's Guide is the first comprehensive book to growing almonds, cashews, chestnuts, hazelnuts, macadamias, pecans, pistachios and walnuts. All aspects of site selection are covered, from soil and climate to aspect and topography through to previous land use and local pest species. Soil preparation, irrigation, planting and propagating trees are also covered. It covers the cultivation and processing of each of the major nut species and also provides guidance on packaging and the wholesale and retail marketing of nuts in Australia and overseas.

1

What’s in a nut?

Nuts are amazing little packages. They taste delicious, they’re one of the most nutritious foods available and dried nuts can be stored without refrigeration. No wonder they became a favoured food by hunter-gatherers and remain a gourmet food today. From a botanical point of view a nut can be defined as a hard-shelled fruit, or a seed containing an edible kernel. Peanuts are not true nuts; they are a type of legume. There are numerous different types of nuts grown around the world, however, the tree nuts grown in Australia are the focus of this book. Tree nuts include almonds, Brazil nuts, cashews, chestnuts, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts.

Nuts that fall from the tree will germinate when planted and the concentrated food reserves within the kernel sustain the young growing plant. This concentrated food reserve provides a rich source of nutrients in the human diet. These nutrients include fats, proteins, carbohydrates and fibre, and also vitamins, minerals and phytochemicals.

The health benefits of nuts

Scientific evidence on the health benefits of nuts has been accumulating for many years as scientific institutions around the world research the properties of nuts and their benefits to human health. In 2003 the Australian Nut Industry Council Ltd launched the ‘Nuts for Life’ program to compile existing information on the health benefits of nuts and communicate this information to health authorities and health professionals.

Scientific research shows that eating nuts regularly is beneficial to health. For instance, four major epidemiological studies have shown that frequent nut consumption confers protection against coronary heart disease, with a level of risk reduction of up to 53% in those eating nuts five or more times a week compared with people eating nuts twice a week or less^1–4. The cardiovascular benefits of nuts have been attributed to their favourable fatty acid profile along with their vitamin E, antioxidants, folate, arginine and phytosterol content.

Epidemiological studies show consumption of tree nuts is associated with a lower risk of prostate cancer⁵ while in vitro and animal studies show potential anti-cancer properties in certain components of tree nuts^6,7. A recent epidemiological study showed that women who ate nuts five or more times a week had 27% lower risk of developing diabetes compared with women who ate nuts twice a week or less⁸. While at present not all tree nuts have been glycemic index tested, pecans and cashews which have been tested have a low glycemic index. Tree nuts also provide monounsaturated fatty acids and contain dietary fibre — all nutritional attributes that assist with optimal glycemic control. Tree nuts are also a source of the amino acid arginine that has been shown to improve insulin sensitivity and reduce the risk of complications in people with diabetes.

Research also shows that higher protein, moderate fat diets may be more effective for weight loss than high carbohydrate, low fat diets due to their beneficial effects on satiety, improved metabolic parametres and an increase in the thermogenic component of the metabolic rate⁹,¹⁰.

Unfortunately, a small percentage of the population have an allergy to nuts. Health officials have reported that the incidence of nut allergies is increasing. Severe reactions (anaphylaxis) can result in death if not treated immediately. Peanut allergies affect 2% of children in the preschool age group and 60% of these children will also have an allergy to a nut other than peanuts. As a result of the increasing incidence of nut allergies in Australia, nuts are becoming a prohibited food for young children at childcare centres and primary schools. It is reported that the processes of maturation, roasting and curing, that increase flavour and shelf life of peanuts, all increase their allergenic properties. These processes are also likely to be important in modifying the allergenic properties of other nuts (Soutter 2004).

What are the healthy substances in nuts?

The following information has been sourced from scientific studies conducted worldwide. These studies are summarised in the Fact Sheets published by Nuts for Life, an initiative of the Australian Nut Industry, Copyright 2003, Horticulture Australia Limited.

Oils

Nuts are a great source of healthy oils. These are the oils that are high in monounsaturated or polyunsaturated fats. Nuts high in monounsaturated fats include macadamias, cashews, almonds, pistachios and pecans. Nuts that are high in polyunsaturated fats include walnuts, hazelnuts, pine nuts and Brazil nuts.

Low glycemic index

Pecans and cashews have a low glycemic index (GI), meaning that the carbohydrate they contain is broken down slowly by the body. The GI of other tree nuts is yet to be tested. Low GI foods assist in the management of weight, blood glucose levels and cholesterol.

Fibre

All nuts contribute fibre to the diet. Dietary fibre helps to lower blood cholesterol and is essential for healthy bowel function.

Vitamin E

Vitamin E is an antioxidant that helps protect tissues in the body from damage.

Folate

Folate is a B vitamin associated with heart health, cancer prevention and decreases the risk of birth defects in babies.

Magnesium

Magnesium is a mineral essential for good nerve and muscle function and for strong bones.

Zinc

Zinc is needed for many processes in the body and is necessary for a strong immune system and healing and protecting the skin.

Selenium

Selenium is essential for a well functioning immune system and thyroid gland. It also helps protect body cells from damage.

Antioxidants

Antioxidants found in nuts include flavonoids and a compound called luteolin. These substances help slow down the aging process and help protect the body from a range of lifestyle related diseases.

Arginine

Arginine is an amino acid that helps keep blood vessels healthy.

Plant sterols

Nuts contain plant sterols that are substances that reduce cholesterol absorption.

Table 1. Nutritional analysis of raw tree nuts

Data obtained from AusNut, Foodworks version 3.01, Xyrus Software unless otherwise indicated. na, not available; nt, not tested. Kilojoule content includes the energy from dietary fibre.

References

1. Kushi, L. H., Folsom, A. R., Prineas, R. J., Mink, P. J., Wu Y., and Bostick, R. M (1996). Dietary antioxidant vitamin and death from coronary heart disease in postmenopausal women. New England Journal of Medicine 34, 1156–1162.
2. Hu, F. B., and Stampfer, M. J. (1998). Nut consumption and risk of coronary heart disease: a review of epidemiologic evidence. Current Athero Reports 1, 205–210.
3. Albert, C. M., Gaziano, M. J., Willet, W. C., and Manson, J. E. (2002). Nut consumption and decreased risk of sudden cardiac death in the Physicians’ Health Study. Archives of International Medicine 162, 1382–1387.
4. Fraser, G. E., Sabate, J., Beeson, W. L., and Strahan, T. M. (1992). A possible protective effect of nut consumption on risk of coronary heart disease. The Adventist Health Study. Archives of International Medicine 152, 1416–1424.
5. Jain, M. G., Hislop, G. T., Howe, G. R., and Ghadirian, P. (1996). Plant foods, antioxidants, and prostate cancer risk: findings from case-control studies in Canada. Nutrition and Cancer 34(2), 178–184.
6. Ip, C., and Lisk, D. J. (1994). Bioactivity of selenium from Brazil nut for cancer prevention and selenoenzyme maintenance. Nutrition and Cancer 1(3), 203–212.
7. Narayanan, B. A., Geoffroy, O., Willingham, M. C., Re, G. G., and Nixon, D. W. (1999). p53/p21WAF1/CIP1 expression and its possible role in G1 arrest and apoptosis in ellagic acid treated cancer cells. Cancer Letters 136(2), 215–221.
8. Jiang, R., Monson J. E., Stampfer J. J., Liu S., Willett W. C., and Hu, F. B. (2002). Nut and peanut butter consumption and risk of Type 2 diabetes in women. Journal of the American Medical Association 288, 2554–2560.
9. Eisenstein, J., Roberts S. B., Dallal, G., and Saltzman, E. (2002). High-protein weight-loss diets: are they safe and do they work? A review of the experimental and epidemiologic data. Nutrition Review 60(7), 189–200.
10. McManus, K., Antinoro, L., and Sacks, F. (2001). A randomised controlled trial of a moderate-fat, low-energy diet compared with a low fat, low-energy diet for weight loss in overweight adults. International Journal of Obesit...

Table of contents

• Cover
• Title
• Copyright
• Acknowledgments
• Foreword
• Contents
• Introduction
• Chapter 1: What’s in a nut?
• Chapter 2: Nut production worldwide
• Chapter 3: What nut grows where
• Chapter 4: Propagation
• Chapter 5: Planting a nut orchard
• Chapter 6: Managing a nut orchard
• Chapter 7: Organic nut production
• Chapter 8: Success in business
• Chapter 9: Almonds
• Chapter 10: Cashews
• Chapter 11: Chestnuts
• Chapter 12: Hazelnuts
• Chapter 13: Macadamias
• Chapter 14: Pecans
• Chapter 15: Pistachios
• Chapter 16: Walnuts
• Chapter 17: Other tree nuts
• Appendix 1: Nut tree notes for gardeners
• Index