Who Cares More about Chemical Defenses - the Macroalgal Producer or Its Main Grazer?

The consequences of defensive secondary metabolite concentrations and interspecific metabolite diversity on grazers have been extensively investigated. Grazers which prefer certain food sources are often found in high abundance on their host and as a result, understanding the interaction between the two is important to understand community structure. The effects of intraspecific diversity, however, on the grazer are not well understood. Within a single, localized geographic area, the Antarctic red seaweed Plocamium sp. produces 15 quantitatively and qualitatively distinct mixtures of halogenated monoterpenes ("chemogroups"). Plocamium sp. is strongly chemically defended which makes it unpalatable to most grazers, except for the amphipod Paradexamine fissicauda. We investigated differences in the feeding and growth rates of both Plocamium sp. and P. fissicauda, in addition to grazer reproductive output, in relation to different chemogroups. Some chemogroups significantly reduced the grazer's feeding rate compared to other chemogroups and a non-chemically defended control. The growth rate of Plocamium sp. did not differ between chemogroups and the growth rates of P. fissicauda also did not show clear patterns between the feeding treatments. Reproductive output, however, was significantly reduced for amphipods on a diet of algae possessing one of the chemogroups when compared to a non-chemically defended control. Hence, intraspecific chemodiversity benefits the producer since certain chemogroups are consumed at a slower rate and the grazer's reproductive output is reduced. Nevertheless, the benefits outweigh the costs to the grazer as it can still feed on its host and closely associates with the alga for protection from predation.

Ocean warming alters predicted microbiome functionality in a common sea urchin.

The microbiome of sea urchins plays a role in maintaining digestive health and innate immunity. Here, we investigated the effects of long-term (90 day) exposure to elevated seawater temperatures on the microbiome of the common, subtropical sea urchin Lytechinus variegatus The community composition and diversity of microbes varied according to the type of sample collected from the sea urchin (seawater, feed, intestines, coelomic fluid, digested pellet and faeces), with the lowest microbial diversity (predominately the order Campylobacterales) located in the intestinal tissue. Sea urchins exposed to near-future seawater temperatures maintained the community structure and diversity of microbes associated with their tissues. However, marginal, non-significant shifts in microbial community structure with elevated temperature resulted in significant changes in predicted metagenomic functions such as membrane transport and amino acid and carbohydrate metabolism. The predicted changes in key metabolic categories suggest that near-future climate-induced increases in seawater temperature could shift microbial community function and impact sea urchin digestive and immune physiology.

Nutritional Profiles of Non-Dairy Plant-Based Cheese Alternatives.

With the growing interest in non-dairy products, there has been a surge of interest in consumers seeking plant-based cheese alternatives spurred by a desire to improve individual health and achieve a more sustainable food supply. The aim of this study was to conduct a cross-sectional survey of non-dairy cheese alternatives available in the United States and to evaluate their nutritional content. A total of 245 non-dairy plant-based cheese alternatives were analyzed using their nutritional facts labels. The various cheese alternatives were based upon coconut oil (n = 106), cashews and coconut (n = 61), cashews (n = 35), oats (n = 16), almonds (n = 7), soy (n = 6), palm fruit oil (n = 5), and other blends (n = 9). Only 3% of these cheese alternatives had 5 g or more of protein, while 19%, 14%, and 1% were fortified with calcium, vitamin B12, and vitamin D, respectively. Almost 60% had high levels of saturated fat, while 15% had low sodium levels. The products based on cashews alone more commonly had the highest protein levels and the lowest sodium and saturated fat levels. Those containing coconut oil more commonly had higher saturated fat and sodium levels and were most frequently fortified with vitamin B12. Few of these products could be considered good dietary sources of either protein or calcium.

Nutritional Content of Non-Dairy Frozen Desserts.

There is a growing interest in non-dairy alternatives fueled by concerns about personal health and the health of the planet. Sales of non-dairy frozen desserts have increased along with other non-dairy alternatives such as plant-based beverages, cheeses, yogurts and creamers. The aim of this study was to conduct a cross-sectional survey of plant-based frozen desserts to determine their nutritional content. A total of 358 plant-based frozen desserts were analyzed from the nutrition label listed on the commercial container. The various products were based upon coconut (n = 126), oat milk (n = 63), almonds (n = 42), cashews (n = 25), soy (n = 11), macadamia milk (n = 9), olive oil (n = 8), faba bean (n = 8), canola oil (n = 8), rice milk (n = 6), sunflower milk (n = 6), avocado (n = 5), pea protein (n = 5) and various fruits, nuts and mixed blends (n = 36). While 90% of the frozen desserts had high sugar levels, 73% had high levels of saturated fat (due to the presence of coconut oil) and only one in four had high levels of fat. None of the products were fortified with calcium, vitamin D or B12, but one in six products had iron levels/serving of at least 10% of Daily Value (DV) and 1 in 6 had protein levels/serving similar to regular dairy ice cream. Food manufacturers need to produce new non-dairy frozen desserts that are more nutritious, since few brands (such as those based upon avocado, apple and hemp protein, or fava bean) presently provide consumers choices with lower saturated fat and sugar levels and/or higher protein levels.

Nutritional Content and Health Profile of Non-Dairy Plant-Based Yogurt Alternatives.

Yogurt is considered a healthy, nutritious food in many cultures. With a significant number of people experiencing dairy intolerance, and support for a more sustainable diet, consumer demand for dairy alternatives has surged. The aim of this study was to conduct a cross-sectional survey of plant-based yogurt alternatives to assess their nutritional content and health profile. A total of 249 non-dairy yogurt alternatives were analyzed from the nutrition label listed on the commercial package. The various yogurt alternatives contained extracts of coconut (n = 79), almonds (n = 62), other nuts or seeds (n = 20), oats (n = 20), legumes (n = 16), and mixed blends (n = 52). At least one-third of the yogurt alternatives had 5 g or more of protein/serving. Only 45% of the yogurt alternatives had calcium levels fortified to at least 10% of daily value (DV), while only about one in five had adequate vitamin D and B12 fortification at the 10% DV level. One-half of the yogurt alternatives had high sugar levels, while 93% were low in sodium. Except for the coconut-based products, the yogurts were not high in fat or saturated fat. The yogurt alternatives were not fortified as frequently or to the same levels as the corresponding non-dairy, plant-based beverages.

Nutritional Content and Health Profile of Single-Serve Non-Dairy Plant-Based Beverages.

A growing number of people are seeking a non-dairy plant-based beverage both for their personal health, and for the health of the planet. The aim of this study was to conduct a cross-sectional survey of single-serve plant-based beverages to assess their nutritional content and health profile. A total of 51 non-dairy plant-based beverages were analyzed from the nutrition label listed on the commercial package. The various beverages contained extracts of soy (n = 14), almonds (n = 13), oats (n = 12), peas (n = 7), banana (n = 2), coconut (n = 2), and rice (n = 1). Almost one-half (45%) of the single-serve beverages had 5 g or more of protein/serving. A total of 75% and 65% of the single-serve beverages had calcium and vitamin B12 levels, respectively, fortified to at least 20% of the Daily Value (DV), while only 28% had vitamin D fortification at the 20% DV level. Two-thirds of the single-serve beverages had high sugar levels, while 39% were low in sodium, 63% were low in fat, and 96% were low in saturated fat. The single-serve plant-based beverages had more protein, calcium, vitamin B12, and sugar but less fat than the non-dairy, multi-serve plant-based beverages/ serving. A limited number of single-serve beverages met the requirements of school meal programs.