Keeping it Fresh: Make Your Juice Last Longer

Jack LaLanne was the world’s first fitness superhero, the “godfather of fitness.” He also really loved juice. The Jack LaLanne Juicer turned juicing into a mainstream practice and juicers into common kitchen equipment.

Research studies have yet to validate claims that juicing is more beneficial than eating whole fruits and vegetables, with some studies suggesting that cleanses or excessive consumption can do more harm than good. Juicing, within reason, is a great way to incorporate these ingredients into your diet if you aren’t naturally inclined to eat your fruits and veggies. There is also something undeniably delightful about a glass of fresh-squeezed juice or the unique flavor combinations that can be created—orange-durian-strawberry-mango-kale, anyone?

Whether you juice for health or to please your palate, here is everything you need to know about how to help your juice stay fresh and vibrantly colored for as long as possible and about selecting the proper juicer for your needs.

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How Juicing Works

Juicing seems like a violent practice. There are gentler ways of retrieving flavor, such as stock making, when we coax flavors from these ingredients as they simmer. Juicing, however, is a form of violence on the biological building blocks of food so that we can unlock the liquid essence within. This means rupturing cells, but the cellular violence is well worth it—juicing yields incredibly rich flavors.

The rich flavors are fleeting, reserved for the freshest juice, which explains why the fresh stuff will always taste better than store-bought counterparts. When we make juice, sugars, acids, and peel oils combine to make the unmistakable flavor of fresh juice; however, over time, the acidity ruins the incredible flavor by destroying the aromatic peel oils over time.

Making the Most of Your Juice

Juicing is only half the battle. Freshly squeezed juice is fleeting. Although cellular destruction is required to release flavor-creating enzymes, as soon as cell walls are ruptured, the clock and biology will start working against you. The same oils that imbue juice with intense flavors and bright colors oxidize quickly. Aromas and flavors begin to diminish as flavor compounds break down.

When we cut open a piece of fruit, we know that it will eventually turn an unappetizing brown. The same applies for the liquid of those fruits. Many juices brown quickly in reaction to the trauma of juicing. Browning is a defense mechanism that plants use to prevent infection. To defend against germs, plants raise antimicrobial defenses. One mechanism is the release of the enzyme polyphenol oxidase (PPO) from tissue, which leads to the production of protective compounds, such as tannins, and to brown color. Pulp presents another issue. It typically browns long before the liquid. Pulp contains high concentrations of oxidizing enzymes and their molecular targets.

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Browning may seem like a strange issue for those of us who are accustomed to purchasing juice at the store. Those juices, however, have already been treated to prevent color change and to preserve flavor. Although juicing is a relatively simple technique, these seven tips, used alone or in combination, will help you to improve your product and get the most out of your produce.

  • First, keep everything cold. Browning is caused by enzymes that respond to heat: for every 10°C/ 18°F drop in temperature, enzymatic activity falls by about half. You can safely chill most fruits to just above freezing before juicing them; however, avoid chilling subtropical produce, such as bananas, mangoes, avocados, and strawberries. Chilling these fruits can induce chilling injury, wherein low temperatures reduce the quality of produce.
  • Freezing produce prior to juicing will also prevent browning. Deep-freezing will permanently destroy the browning enzymes; however, flavor-creating enzymes might take a bit of a hit. If you decide to freeze your produce, thaw prior to juicing, unless you want to have a smoothie on your hands.
  • A three-minute dip in boiling water destroys browning enzymes. Blanching requires high temperatures, though, which will partially cook food by the time the enzymes break down.
  • Although some of us prefer a little pulp in our juice, filtering it out will eliminate the tissue that enzymes act on to form brown pigments.
  • Try lowering the pH of your juice. The more acidic the juice, the slower the enzymatic reactions that cause discoloration. High acidity also acts directly on brown pigments to lighten their color.
  • If you own a vacuum sealer, use it to help prevent oxidation. Although some oxygen is dissolved into the juice itself, vacuum sealing the juice will help slow down browning by removing oxygen.
  • Natural preservatives are another way to retain color and restore flavor. Ingredients like ascorbic acid (vitamin C), citric acid, malic acid, and honey will prevent browning, while essential oil, alpha tocopherol (vitamin E), or even a squirt of fresh juice from a different batch will preserve flavor.

Picking a Juicer

The type of juicier you own will also make an impact on your juice. Devout juicing advocates prefer cold-press juicers over equipment that introduces any heat to the process. In truth, the mechanisms that make each juicer work can affect the quality of your product, yield size, and even what types of produce you can juice.

Centrifugal-style juicers:

Centrifugal-style juicers are similar to blenders—they pulverize food with a broad, flat blade that sits at the bottom of a spinning mesh basket. The pulverized food is flung against the basket wall, where centrifugal force expels most of the juice from the pulp through the mesh and into a waiting container. These juicers handle both fruits and vegetables well, but look for machines that are designed to automatically dispel pulp deposits to make cleaning easier and to prevent clogs forming in the basket. With centrifugal force comes one major drawback: the friction of the force oxidizes the juice faster, which damages the flavor and color. You’ll also find that the yield from these machines is smaller than its Champion-style counterpart.

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Champion-style juicers:

Champion-styles juicers are workhorses. Food is pushed down a chute onto a serrated, rotating blade. As fruits and vegetables pass through the blades, cell walls rupture, releasing their contents, which rapidly collect in a bowl. These appliances excel at separating solids from liquids: pulp is discarded into a separate waste receptacle. Champion-style juicers are also ideal for juicing relatively dry foods, like wheatgrass or leafy greens that can be difficult for other machines to pulverize. The primary shortcoming of this style of juicer is that the pulp still retains some liquid, which reduces overall yield.

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Food presses:

Food presses or cold-press juicers (also known as masticating juicers) force liquids out mechanically by squeezing food between two hard, unyielding surfaces, one of which is perforated. These machines, which theoretically seem like a medieval torture device for fruits and vegetables, are often preferred by serious juicers because they use less heat. Juice presses are great for softer foods or for foods that have been softened with sugar, enzymes, or a little heat. In some presses, including cider presses, food is placed between flat plates, often between multiple layers of plates. Citrus fruit presses accommodate the shapes of citrus fruits by using convex and concave pressing surfaces. Muscle power fuels juice presses, which causes juice yields to vary depending on the user. If you enjoy pulp in you juice beware— your juice will contain fewer particles because food is compressed, as opposed to being torn or shredded.

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