Clean Label Solutions For Frying Oil Stabilisation

A move to healthier, naturally sourced stabilisers is a must for food manufacturers to continue delivering the great flavours and textures consumers crave, while also meeting their healthy eating demands. By Cindy Tian, Kalsec Lead Scientist.

Consumers have an undeniable affinity for fried foods. Their enticing flavours, crunchy textures and overall convenience make them a favourite in cuisines throughout the world. At the same time, fried foods have a common perception of being unhealthy, and that is rooted in the processes and ingredients that have been used to stabilise the oils foods are fried in.

Oils have always posed a challenge for food manufacturers because of their tendency to oxidise and generate off-flavours, especially under the influence of heat, light and heavy metals. This not only impacts the flavour, but also the shelf-life of fried foods. As such, stabilisers are a critical component of frying oils.

The problem is that, historically, stabilisation occurred by using more saturated fats or through hydrogenation, which results in artificial trans-fats. Because most fried foods contain a significant amount of oil, these ingredients really do matter.

In addition to health implications, trans-fats and saturated fats also run contrary to the trend toward clean labels—a trend that shows no signs of slowing down.

In fact, from 2008 to 2018, global launches of new products with ethical and clean label claims increased by 25 percent. This includes claims such as “natural,” “no additives,” “no preservatives” or “organic” (Innova, 2019). A survey conducted by Kalsec in 2018 further supports this; it stated that 41 percent of global consumers said a “no artificial ingredients” claim would influence their decision to switch brands or products.

A move to healthier, naturally sourced stabilisers is a must for food manufacturers to continue delivering the great flavours and textures consumers crave, while also meeting their healthy eating demands.

The Power And Possibility Of Naturally Sourced Antioxidants

Antioxidants are an alternative to trans-fats and saturated fats for oil stabilisation, and naturally sourced antioxidants help deliver the clean label consumers are looking for.

Rosemary extracts, for example, work by reducing the radical load in the oil, which limits and slows down oxidative damage. Furthermore, chelators deactivate metals that initiate oxidation while oxygen scavengers react with and remove oxygen from the food system, thereby, improving shelf-life.

Rosemary (Rosmarinus officinalis L.) is an aromatic herb which belongs to the family of Lamiaceae. Rosemary extracts are prepared by drying, grinding and extracting the needles of the plant, and are found to have high efficacy in a number of applications, including oils, because they possess a broad range of antioxidant phenolic compounds (Berdahl and McKeague 2015).

A drawback, however, is the strong flavour and aroma imparted by the herb. Kalsec countered this problem with a line of products called Herbalox XT. They provide the same antioxidant strength but with only 10 percent of the flavour of regular rosemary extracts, making them ideal for oils.

Another advantage of naturally sourced antioxidants is the ability to combine them into synergistic blends. A secondary antioxidant can be added to rosemary extract, for example, to regenerate it and better control oxidation in different locations and at different stages—a necessary consideration for the complex degradation of frying oils. Duralox Oxidation Management Systems crafted by Kalsec deliver these synergistic effects and are designed to meet the unique needs of different applications and processing conditions.

Successful Outcomes For Healthier Fried Foods

The complexity of frying oil degradation requires strict process control and a sophisticated antioxidant system to ensure oil quality. They can be added before frying to inhibit oxidation early in the process. After frying, antioxidants can be topically applied with spray oil or slurry for additional protection. In some cases, antioxidants are also added into breading, coating or fillings to provide extra protection.

Kalsec’s Herbalox Rosemary Extract and Duralox products demonstrate strong capabilities in controlling oxidation of frying oil, as well as improving oxidative stability of fried food. For frying applications, it is especially beneficial to use Duralox solutions that are composed of antioxidants with different modes of action. Duralox systems are also found to be effective in highly unstable applications such as fish oils, and complex matrices such as bakery and snack foods.

Efficacy of Duralox Systems in potato chips

In one recent Kalsec frying study, the efficacy of Duralox products in soybean oil was compared against three synthetic additives or blends.

Methodology

All antioxidants were added to Refined, Bleached and Deodorised (RBD) soybean oil and mixed well prior to frying. Fresh potato slices were fried at 180°C for three minutes for a total of 12 hours within two consecutive days. Oil quality was determined by measuring Total Polar Compounds % (TPC%). When oil oxidises, the oxidation compounds being formed are more polar than the starting triglycerides (TGs). A higher TPC% value indicates more severe oil degradation. After frying, potato chips were collected and stored at 40 deg C for 26 weeks. Hexanal generated due to oxidation of the chips was monitored using static headspace gas chromatography.

Results

Kalsec’s Duralox products showed comparable results to the synthetic antioxidants (Figure 2). TBHQ, the best performing synthetic antioxidant in this test, reduced TPC% by 19.7%. Duralox NM-110 reduced the TPC% by 20.4% and Duralox AN-110 reduced it by 14.6%.

The Duralox systems also showed equal or better performance than the BHA/BHT blend or a blend of ascorbyl palmitate and mixed tocopherols (AP + MT). The quality of the oil significantly affected the stability of the chips. As a result, chips fried in oils treated with Duralox products were found to be more stable than the control and provided similar levels of protection as TBHQ (Figure 3).

Efficacy Of Herbalox Rosemary Extract And Duralox Systems In Fried noodles

Fried instant noodles are consumed in significant amounts in Asia. According to the World Instant Noodle Association’s May 2019 report, 108 billion servings of instant noodles were consumed in 2018. There has been a lot of expressed interests in extending the shelf-life of these products, so Kalsec conducted several studies to learn how natural antioxidants might help.

Methodology

Herbalox XT-O, Duralox AN-110, XT, mixed tocopherols and a commercial green tea extract were dosed into oil before frying. Noodles were made and fried in palm oil at 190 deg C. An accelerated shelf-life study was conducted by measuring hexanal formed in the noodle as well as oxidised aroma and flavour.

Results

Herbalox and Duralox Systems both suppressed formation of oxidation compounds during extensive periods of storage (Figure 4).

In addition, the stability of fresh palm oil was evaluated using the Oxidative Stability Instrument according to AOCS Official Method Cd 12b-92. Herbalox and Duralox Systems both extended the induction time of palm oil, leading to a more stable oil for use in various applications (Figure 7).

Duralox AN-110, XT also effectively inhibited formation of off-odors and off-flavors in the noodle (Figure 5 and 6). This is strong evidence that a synergistic combination of antioxidants can provide better protection for complex applications.

In addition, the stability of fresh palm oil was evaluated using the Oxidative Stability Instrument according to AOCS Official Method Cd 12b-92. Herbalox and Duralox Systems both extended the induction time of palm oil, leading to a more stable oil for use in various applications (Figure 7).

The Future Of Clean Label Oils

Even in fried foods, consumers are looking for healthier, clean-label products. Kalsec Herbalox and Duralox Oxidation Management Systems deliver clean and natural alternatives to hydrogenated oils that demonstrate strong capabilities in controlling oxidation of frying oil, as well as improving the oxidative stability of various fried foods. In some cases, they showed comparable performance to synthetic antioxidants, and thus can be used as clean label alternatives for these ingredients. In complex applications like frying, it is especially beneficial to use Duralox Systems that are composed of antioxidants with different modes of action resulting in synergistic protection of the oils.

Check these articles out:

Clean Label Solutions For Frying Oil Stabilisation

Snack Manufacturing: Potato Chip Manufacturing Thrives On Efficiency

Palsgaard Achieves Total Carbon-Neutral Production

Three Fake Milk Plants Busted In India