Month: June 2023
50 facts about food microbiology!
Fermented vegetables for health
Tsukemono is a traditional Japanese term that refers to a variety of pickled vegetables. It is a popular side dish and condiment in Japanese cuisine, often served alongside meals to provide a balance of flavors and textures. Tsukemono can range from simple salted pickles to more complex, seasoned and fermented varieties. The process of making tsukemono typically involves preserving vegetables in a brine or salt to extract moisture and promote fermentation. This fermentation process can vary in duration, from a few hours to several months, depending on the desired flavor and texture. The brine or salt mixture may also contain additional seasonings like rice bran, vinegar, soy sauce, miso, or spices to impart different flavors. There are numerous types of tsukemono, each with its unique taste and characteristics. Some common examples include: Tsukemono can vary in taste, texture, and appearance depending on the region, ingredients, and preparation methods. They add a vibrant and refreshing element to Japanese meals, providing a balance of flavors to complement the main dishes. Escabeche is a traditional dish and cooking technique that has roots in Spanish cuisine but is also prevalent in Latin American, Filipino, and Mediterranean cuisines. The term “escabeche” refers to a method of preserving and flavoring food by marinating it in a vinegar-based sauce or marinade. In its most common form, escabeche typically involves fish or meat that is first cooked, then immersed in a marinade composed of vinegar, oil, onions, garlic, and various herbs and spices. The dish is then left to marinate for a period of time, allowing the flavors to meld together and the protein to absorb the tangy and aromatic characteristics of the marinade. The marinade used in escabeche can vary depending on the regional and cultural influences. Some common ingredients used in the marinade include: The marinated protein, whether fish or meat, is typically served cold or at room temperature. The marinade not only imparts flavor but also acts as a preservative, allowing the dish to be enjoyed over an extended period. It is common to find escabeche served as an appetizer, a side dish, or even as a main course, accompanied by rice, bread, or other side dishes. Escabeche can be versatile, with variations in different regions and cultures. For example, in the Philippines, it is often made with fried fish and served as a popular dish called “escabeche de pescado.” Overall, escabeche offers a unique blend of flavors, combining the acidity of the vinegar, the richness of the oil, and the aromatic herbs and spices. It provides a tangy and savory addition to the culinary landscape. Pickled watermelon rind is a unique and flavorful food product made from the rind or peel of watermelon, which is typically discarded. Instead of being wasted, the rind is preserved and transformed into a tangy and sweet pickled delicacy. The process of making pickled watermelon rind involves removing the green outer skin and any remaining pink flesh from the watermelon rind. The rind is then typically cut into bite-sized pieces or strips, although shapes can vary depending on personal preference and regional traditions. The rind is then soaked in a brine solution containing vinegar, sugar, and various spices and seasonings. The brine helps to impart flavor, preserve the rind, and balance the natural sweetness with acidity. Commonly used spices and seasonings include cinnamon, cloves, ginger, allspice, and sometimes chili peppers for a touch of heat. After soaking in the brine for a period of time, which can range from a few days to several weeks, the watermelon rind absorbs the flavors and undergoes a transformation. The result is a pickled watermelon rind with a firm yet tender texture and a sweet and tangy taste profile. The rind retains some of its natural sweetness while being infused with the flavors of the brine and spices. Pickled watermelon rind is often enjoyed as a snack or side dish. It can be eaten on its own or paired with other foods like cheese or cured meats. In some regions, it is also used as a condiment or relish, adding a unique touch to sandwiches or salads. The pickling process not only enhances the flavor and texture of the watermelon rind but also helps to extend its shelf life, allowing it to be enjoyed for an extended period. It is a delightful example of utilizing a typically discarded part of the watermelon and transforming it into a delicious and versatile culinary treat.
Bacteria, carotenoids and eye health
This piece of work was submitted by Weny Tjong, as a 3rd-year student in the School of Applied Sciences at RMIT University in 2008. It was part of a wider body of work looking at the potential to have bacterial sources of zeaxanthin incorporated into novel functional food products, a different perspective on food microbiology. This blog article covers an introduction to carotenoids, their importance in eye health and then some microbial sources of zeaxanthin. The idea is that these species could form the basis of microbiology processes for industrial production of zeaxanthin for incorporation into food. What are carotenoids? Carotenoids are liposoluble tetraterpenes, they are widely distributed pigments occurring in flowering plants, algae, fungi and bacteria, and also in animals as diverse as birds and crustaceans (Schieber & Carle, 2005). They can only be synthesised by plants and bacteria, and thus their presence in animals is due to ingestion via food and subsequent accumulation in certain tissues. In plants, these carotenoids are localized in subcellular organelles (plastids), such as chloroplasts and chromoplasts. There are two main classes of naturally occurring carotenoids: carotenes and xanthophylls (Saljita, Singhal & Kamat, 2008). Carotenes are hydrocarbons that are either linear or cyclised at one or both ends of the molecule, whereas xanthophylls are the oxygenated derivatives of carotenes. Examples of carotenes include β-carotene and α-carotene, and xanthophylls include violaxanthin, antheraxanthin, zeaxanthin, neoxanthin and lutein. Carotenoids have a conjugated double bond system that constitutes the light absorbing chromophore which gives them their bright colour, and presence in the visible absorption spectrum which aids their identification and quantification (Sajilata, Singhal & Kamat, 2008). All-trans isomers strongly absorb visible light in region between 400 and 500 nm, while cis-isomers absorb light in the near UV region (~ 320 nm). Carotenoids in eye health The carotenoids lutein and zeaxanthin may be beneficial to macular health as they are the only carotenoids found in the eye (Jones, 2007). This is also supported by Yeum et al., 1996 and Updike & Schwartz, 2003. Their data indicate that the main carotenoids present in both human macula and lenses are lutein and zeaxanthin. Lutein and zeaxanthin are therefore the primary components of the human macula pigment. Lutein and zeaxanthin concentration is found to be approximately 500 times higher than the concentration in other tissues (Mares-Perlman et al., 2002). Zeaxanthin is more prominent in the inner macula whereas lutein is more dominant away from the fovea. This distribution of lutein and zeaxanthin in the retina suggests the possible role of lutein in protecting the rods that are concentrated in the peripheral retina and zeaxanthin in protecting the cones that are concentrated in the central retina. Bone et al. 1998 has proposed that the role of these macular pigments may be two-fold: to improve visual acuity and to protect the retinal tissues against photo-degradation. Microbial sources of zexanthin Microbial production of zeaxanthin has gained some interest in the nutraceutical industry. As they are amongst the few microbes that synthesize zeaxanthin as their predominant carotenoid, the choice of the microbial source is critical. The determination of which microorganism produces higher yield of zeaxanthin is carried out by performing HPLC analysis with ultraviolet/visible or photodiode array detection on the extracted carotenoids from the microorganisms (Gierhart, 1995). Sphingobacterium multivorum Zeaxanthin is essentially the only carotenoid produced by Sphingobacterium multivorum. The pigment formed by this species consists of 95% to 99% zeaxanthin, with the zeaxanthin produced being identical to that of Zea mays (Gierhart, 1995). Since β-carotene and β-cryptoxanthin are the precursors in biosynthesis of zeaxanthin, their presence (~ 5% to 10%) is observed during the initial growth phases of Sphingobacterium multivorum The hydroxylation of these precursors subsequently leads to zeaxanthin. Sphingobacterium multivorum cultures are able to produce up to 190 mg zeaxanthin per litre, with specific cell concentration of 16 mg per gram dried cellular mass (Sajilata, Singhal & Kamat, 2008). These cultures are grown in media containing glucose or sucrose, sulphur-containing amino acids such as methionie, cysteine or cystine, pyridoxine, and bivalent metal ions such as Fe2+ ,Co2+ ,Mo2+ or Mn2+. Erwinia herbicola Erwinia herbicola is a non photosynthetic bacterium which is yellow in colour due to accumulation of mono- and di- glucosides of zeaxanthin carotenoids (Sajilata, Singhal & Kamat, 2008). Neospongioccoccum Neospongioccoccum is one of FDA approved generally regarded as safe (GRAS) strains which has been added into poultry feed to enhance their yellow pigmentation (Sajilata, Singhal & Kamat, 2008). In addition, it is known that the green alga Neospongiococcum excentricum produces up to 0.65% xanthophylls on the dry basis. Spirulina Sajilata, Singhal & Kamat, 2008 has reviewed that this blue-green alga has been fed to cultured prawns to enhance their carapace colour. The zeaxanthin produced by Spirulina, is converted into astaxanthin responsible for the colour enhancement. In the case of broiled chicken, accumulation of zeaxanthin within the flesh is provided by Spirulina, which increases the yellowness and redness in it. There are many more other microbial sources of zeaxanthin. Among these are Dunaliella salina, Synechocystis sp, Microcystis aeruginosa, and Phaffia rhodozyma. The details of these are available in Sajilata, Singhal & Kamat, 2008. References Bone, R. A., Landrum, J. T., Fernandez, L. Tarsis, S. L. (1988). Analysis of the macular pigment by HPLC retinal distribution and age study. Investigative Ophthalmology & Visual Science, 29(6), 843-849. Gierhart, D. L. & Applied Food Biotechnology Inc. (1995). Zeaxanthin-containing compositions produced by Flavobacterium multivorum. U.S. patent 5,427,783. date of issue June 27 1995. Jones, A. A. (2007). Age related macular degeneration: should your patients be taking additional supplements. Australian Family Physician, 36(12), 1026-1028. Mares-Perlman, J. A., Millen, A. E., Ficek, T. L & Hankinson, S. E. (2002). The body evidence to support a protective role for lutein and zeaxanthin in delaying chronic disease. The Journal of Nutrition, 132, 518S-524S. Sajilata, M. G., Singhal, R.S. & Kamat, M. Y. (2008). The carotenoid pigment zeaxanthin. Food Science and Food Safety, 7, 29-49. Schieber, A. & Carle, R. (2005). Occurrence of carotenoid cis-isomers in food: technological, analytical, and nutritional
Selling food products from home in Alabama – understanding cottage food laws.
In Alabama, the regulation and oversight of food safety standards, including cottage food laws, are handled by different regulatory bodies. Let’s explore each of these bodies and their roles: Cottage food laws in Alabama allow individuals to produce certain types of food products in their home kitchens for sale to the public. These laws provide opportunities for small-scale entrepreneurs to start their food businesses without the need for a commercial kitchen facility. Here are the key details of cottage food laws in Alabama: Allowed Cottage Food Products:Under Alabama’s Cottage Food Law, individuals can produce specific non-potentially hazardous food items. The allowable cottage food products include: Prohibited Foods:The Cottage Food Law in Alabama does not permit the production of potentially hazardous food items, including: Sales Limitations:Cottage food operations in Alabama have sales limitations. As of September 2021, the total annual gross sales of cottage food products cannot exceed $20 000 USD. Labeling Requirements:Proper labeling of cottage food products is essential to inform consumers about the ingredients and potential allergens. The following labeling requirements apply to cottage food products in Alabama: Other Requirements:To operate a cottage food business in Alabama, certain additional requirements must be met: It is important to note that the details of cottage food laws can change over time. Therefore, it is advisable to consult the official websites of the Alabama Department of Agriculture and Industries (ADAI) or seek guidance from the relevant regulatory authorities to ensure compliance with the most up-to-date requirements. In summary, the Alabama Department of Public Health, along with the County Health Departments, is primarily responsible for overseeing food safety standards for all food establishments in the state. The Alabama Department of Agriculture and Industries specifically regulates cottage food operations and ensures compliance with the Cottage Food Law. These regulatory bodies work together to maintain food safety and protect public health throughout Alabama.
Food safety regulations of the world – Part 6, South America.
Wednesday this week, June 7, was World Food Safety Day. The World Health Organization has stated this year’s theme was “Food standards save lives”. To provide an introductory overview of the food safety regulatory framework around the world, we are giving an overview each day this week of the food safety regulations in the three most populous countries on each inhabited continent. This is part 6 of 6, South America, where we look into Brazil, Columbia and Argentina. Food safety regulations in Brazil – Brazilian Ministry of Agriculture, Livestock, and Food Supply (MAPA) and the Brazilian Health Regulatory Agency (ANVISA). Here are some key aspects of food safety regulations in Brazil: Food safety regulations in Colombia – Colombian Ministry of Health and Social Protection (Ministerio de Salud y Protección Social) and the Colombian Agricultural Institute (Instituto Colombiano Agropecuario – ICA). Here are some key aspects of food safety regulations in Colombia: Food safety regulations in Argentina – Argentine Food Safety and Quality Service (Servicio Nacional de Sanidad y Calidad Agroalimentaria – SENASA) and the National Administration of Medicines, Food and Medical Technology (Administración Nacional de Medicamentos, Alimentos y TecnologÃa Médica – ANMAT). Here are some key aspects of food safety regulations in Argentina:
